Enhancing the accumulation of beta-amyrin in Saccharomyces cerevisiae by co-expression of Glycyrrhiza uralensis squalene synthase 1 and beta-amyrin synthase genes / 药学学报

ABSTRACT

Glycyrrhiza uralensis Fisch. ex DC is widely used in traditional Chinese medicine (TCM). Among its various active components, glycyrrhizic acid is believed to be the marker component. Squalene synthase (SQS) and beta-amyrin synthase (beta-AS) are key enzymes in the biosynthetic pathway of glycyrrhizic acid in G uralensis. To reveal the effects of co-expression of SQS1 and beta-AS genes on this pathway, 7 yeast expression vectors harboring different SQS1 variants and beta-AS were constructed and expressed in Saccharomyces cerevisiae as fusion proteins. TLC and GC-MS results showed that co-expression of SQS1 and beta-AS enhanced the accumulation of beta-amyrin. The effects of SQS12 were more obvious than the other two SQS1 variants. This study is significant for further investigations concerned with exploring the biosynthesis of glycyrrhizic acid in vitro and strengthening the efficacy of G. uralensis by means of increasing the content of glycyrrhizic acid.