An Overview of 7α- and 7β-Hydroxysteroid Dehydrogenases: Structure, Specificity and Practical Application

7 alpha-Hydroxysteroid dehydrogenase and 7 beta-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 7 alpha-hydroxysteroid dehydrogenase and 7 beta-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.

Automated summary

This article summarizes the structural characteristics, specificities, biochemical properties, and applications of 7 alpha-hydroxysteroid dehydrogenase and 7 beta-hydroxysteroid dehydrogenase. Emphasis is placed on obtaining novel enzymes that are thermally stable and active under specific conditions.