catalytic properties of flavanone-3-hydroxylase from different plants

Abstract:

[Background] Flavanone-3-hydroxylase (F3H) is one of the key enzymes in the metabolic pathway of flavonoids.The catalytic properties of F3H from different plants may be different,which has an important impact on the biosynthesis of flavonoids.[Objective] In order to compare and analyze the enzymatic properties and catalytic abilities of F3H,providing reference for the selection of F3H in the metabolic engineering of flavonoids in the future.[Methods] Three genes,CsF3H(Camellia sinensis),GbF3H(Ginkgo biloba) and GmF3H(Glycine max),were identified by phylogenetic analysis.The three F3H were purified by affinity chromatography,and the enzymatic properties were characterized by naringenin as substrate in vitro.Single-factor culture method was used to analyze the activities of F3H in Escherichia coli and Saccharomyces cerevisiae.[Results] Enzymatic analysis showed that the optimal temperature of CsF3H,GbF3H and GmF3H was 40,40 and 35℃,and the optimal pH was 7.5,7.0 and 7.5,respectively.The k_cat/K_m of CsF3H was 0.36 L/(mmol·s),which was higher than that of GbF3H and GmF3H.When substrate naringenin concentration was 500 μmol/L,the conversion rate was more than 80% of the E.coli contained CsF3H,GmF3H,while the strain contained GbF3H was only 23.8%.As for the S.cerevisiae with different F3H,the conversion efficiency was 40%,with no significant difference.[Conclusion] There were different catalytic activities of F3H from different plants.Moreover,one F3H also showed great differences within prokaryotic and eukaryotic chassis cells.CsF3H has excellent catalytic capacity and showed better development and application potential in prokaryotic chassis cells.