Enzymatic Nanoreactors for Environmentally Benign Biotransformations.1.Formation and Catalytic Activity of Supramolecular Complexes of Laccase and Linear-Dendritic Block Copolymers

摘要

We describe the construction of enzymatic nanoreactors through noncovalent envelopment of a glycoprotein by amphiphilic linear-dendritic AB or ABA copolymers.The synthetic procedure is based on the regioselective adsorption of dendritic poly(benzyl ether)-block-linear poly(ethylene glycol)-block-dendritic poly(benzyl ether) or linear poly(ethylene oxide)-block-dendritic poly(benzyl ether) copolymers onto the oxidative enzyme laccase from Trametes versicolor in aqueous medium.The complexes formed have improved catalytic activity compared with the native enzyme (77-85 nkat/mL vs 60 nkat/mL,respectively) and are more stable at elevated temperatures up to 70 °C.Experiments with deglycosylated laccase confirm that the glycoside fragments in the native enzyme serve as the anchor sites for the linear-dendritic copolymers.The enzymatic nanoreactors are able to effectively oxidize series of substrates;phenolic compounds (syringaldazine) and hydrophobic polyaromatic hydrocarbons (anthracene and benzo[a]pyrene) under "green" chemistry conditions.