Regioselective syntheses of glycosides using modern chemical methods suffer from the need to invoke multiple steps of protection and deprotection, and even then product mixtures may occur. Discovering and tuning by mutagenesis glycosyltransferases (GTs) with considerable substrate promiscuity is an alternative challenge. We tuned by rational design based on extended Focused Rational Iterative Site-specific Mutagenesis (FRISM) a newly identified GT from Siraitia grosvenorii (UGT74AC2) as the catalyst in the targeted regioselective glucosylation of the polyhydroxy substrate silybin and derivatives. A handful of mutants was constructed with a restricted set of rationally chosen amino acids, providing variants showing 94%, > 99% and > 99% selectivity on the 3-OH, 7-OH and 3,7-O-diglycoside, respectively, compared with the wildtype resulting in a 22%:39%:39% product mixture. Remarkably, even N- and S-glucosylation was achieved. Docking and molecular dynamics (MD) simulations studies shed light on the origin of regioselectivity. These findings can be invoked to guide future enzymatic tailoring of UGTs in the production of flavonoids as potent pharmaceuticals and of other useful compounds.

Jiao Li

Ge Qu

Na Shang

Peng Chen

Yan Men

Weidong Liu

Zelong Mei

Yuanxia Sun

Zhoutong Sun

Green Synthesis and Catalysis

Near-perfect control of the regioselective glucosylation enabled by rational design of glycosyltransferases

Docking and molecular dynamics simulations studies shed light on the origin of regioselectivity and can be invoked to guide future enzymatic tailoring of UGTs in the production of flavonoids as potent pharmaceuticals and of other useful compounds.

理性设计糖基转移酶实现区域选择性糖基化的近乎完美控制

Near-perfect control of the regioselective glucosylation enabled by rational design of glycosyltransferases

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Journal Info

Category	Quartile
CHEMISTRY, MULTIDISCIPLINARY	1