Exploiting the Reversibility of GT_BP1 Catalyzed One-pot Reactions for the Synergistical Synthesis of Ponasterone A and Phenolic Glycosides

In the process of glycosyltransferase-catalyzed transglycosylation, the synthesis of uridine diphosphate sugars is generally thermodynamically disfavored. This study found that GT_BP1 from Bacillus pumilus BF1 displayed the potential to reversely synthesize uridine diphosphate glucose (UDPG, UDP-glucose), which catalyzed the deglycosylation of ponasteroside A and the transglycosylation of phenolic compounds in one-pot reaction. Sequence alignment and phylogenetic tree analysis of GT_BP1 and other GTs with reversible glycosylation ability were also implemented. Using solvent engineering strategy, the reaction time in water-organic biphasic was shortened and the conversion was improved. The final conversion of ponasterone A was reached 93.4%, and the final yield of ferulic acid glycoside was 92.7%. Using the fed-batch technology with the coupled reaction, the cumulative product of ponasterone A was about 1.97 g/L, and the level of produced ferulic acid glycoside was about 1.52 g/L. The substrate specificity of the GT_BP1 was also confirmed. It implies the diversity of GT_BP1’s ability to construct UDP cycles.