Quercetin (QCT), a prominent natural flavonoid, is limited in clinical applications by its poor water solubility and bioavailability. This study employs site-directed mutagenesis of glycosyltransferase UGT78D2 to enhance QCT glycoside synthesis. Recombinant Escherichia coli systems expressing wild-type UGT78D2 and three mutants (F18D, S150V, Q88F) were developed, with optimized induction conditions (0.4 mM IPTG, 25°C, 12 h). A whole-cell cascade biocatalysis platform coupling UGT78D2 with sucrose synthase (AtSUS1) enabled in situ UDP-glucose regeneration from sucrose. Using QCT and kaempferol (Kae) as substrates, reaction conditions were optimized, resulting in 31.2% and 54.9% relative yield increases for the Q88F mutant, respectively. AI-assisted mutant design and data analysis further validated these improvements. These findings provide insights for scalable flavonoid glycosylation and sustainable bioprocessing.

Zihan Zhang.Engineering UGT78D2 Glycosyltransferase via Site-Directed Mutagenesis for Enhanced Quercetin and Kaempferol Glycosylation in a Whole-Cell Cascade System. International Journal of Health and Pharmaceutical Medicine (2025), Vol. 5, Issue 1: 43-56. https://doi.org/10.38007/IJHPM.2025.050105.

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