Heterologous biosynthesis of medicarpin using engineered Saccharomyces cerevisiae

Medicarpin is an important bioactive compound with multiple medicinal activities, including anti-tumor, anti-osteoporosis, and anti-bacterial effects. Medicarpin is associated with pterocarpans derived from medicinal plants, such as Sophora japonica, Glycyrrhiza uralensis Fisch., and Glycyrrhiza glabra L. However, these medicinal plants contain only low amounts of medicarpin. Moreover, the planting area for medicarpin-producing plants is limited; consequently, the current medicarpin supply cannot meet the high demands of medicinal markets. In this study, eight key genes involved in medicarpin biosynthesis were identified using comparative transcriptome and bioinformatic analyses. In vitro and in vivo enzymatic reaction confirmed the catalytic functions of candidate enzymes responsible for the biosynthesis of medicarpin and medicarpin intermediates. Further engineering of these genes in Saccharomyces cerevisiae achieved the heterologous biosynthesis of medicarpin using liquiritigenin as a substrate, with a final medicarpin yield of 0.82 ± 0.18 mg/L. By increasing the gene copy numbers of vestitone reductase (VR) and pterocarpan synthase (PTS), the final medicarpin yield was increased to 2.05 ± 0.72 mg/L. This study provides a solid foundation for the economic and sustainable production of medicarpin through a synthetic biology strategy.