Title:An Overview of 7α- and 7β-Hydroxysteroid Dehydrogenases: Structure, Specificity and Practical Application
Volume: 28
Issue: 11
Author(s): Deshuai Lou, Xi Liu and Jun Tan*
Affiliation:
- Chongqing Key Laboratory of Medicinal Resources in the Three Gorges Reservoir Region, School of Biological and Chemical Engineering, Chongqing University of Education, Chongqing 400067,China
Keywords:
7α-hydroxysteroid dehydrogenase, 7β-hydroxysteroid dehydrogenase, short-chain dehydrogenase/reductase, substrate
specificity, coenzyme specificity, stereoselectivity, protein engineering.
Abstract: 7α-Hydroxysteroid dehydrogenase and 7β-hydroxysteroid dehydrogenase are key enzymes
involved in bile acid metabolism. They catalyze the epimerization of a hydroxyl group
through 7-keto bile acid intermediates. Basic research of the two enzymes has focused on exploring
new enzymes and the structure-function relationship. The application research focused on the
in vitro biosynthesis of bile acid drugs and the exploration and improvement of their catalytic ability
based on molecular engineering. This article summarized the primary and advanced structural
characteristics, specificities, biochemical properties, and applications of the two enzymes. The emphasis
is also given to obtaining novel 7α-hydroxysteroid dehydrogenase and 7β-hydroxysteroid dehydrogenase
that are thermally stable and active in the presence of organic solvents, high substrate
concentration, and extreme pH values. To achieve these goals, enzyme redesigning based on protein
engineering and genomics may be the most useful approaches.