Remodeling the Active Site of Sucrose Phosphorylase for Effective Resveratrol Glycosylation

The plasticity of the enzyme active site is widespread in naturally evolved homologous enzymes, but has been less explored in engineered enzymes. In this study, the plasticity of the active site in sucrose phosphorylases (SPs) for 3-O-α-glucopyranosyl-resveratrol synthesis was obtained. The mutant R135L/Y344Q of BlSP from Bifidobacterium lactis showed the same catalytic activity with the previous mutant Q345F, but displayed different microenvironment of active site and enzymatic properties. The new mutant could almost completely convert up to 15 g/L resveratrol into resveratrol glycoside without cosolvent, meanwhile, generate a new impurity 3-O-α-diglucoside-resveratrol, which was identified as 3-O-α-maltosyl-resveratrol.