Engineering Glycosyltransferase by Semi-Rational Design for Highly Regioselective Synthesis of Polydatin

Polydatin, a 3- O -glucoside of resveratrol, shows an enhanced aqueous solubility and bioactivity. The UDP-glucose-dependent glycosyltransferase UGT BL 1, derived from Bacillus licheniformis ZSP01, glycosylates resveratrol but exhibits promiscuous regioselectivity. To regulate the region-specific glycosylation of resveratrol, this study employed a strategy involving deletion modification. Specifically, the amino acids 62I and 63D, located on the loop, were deleted to create the mutant Δ(62–63), resulting in an increase in polydatin’s regioselectivity from 12.2% in the wild type to around 90.0%. Molecular docking and dynamics simulations were conducted to analyze the local flexibility of this region. This flexibility brings the protein skeleton closer to the active center, facilitating interactions between the 3-OH group of resveratrol and the amino acid residues surrounding the active center, ultimately promoting the formation of polydatin.