Polymer grafting from a metallo‐centered enzyme improves activity in non‐native environments

Metallo-centered enzymes have found applications in environmental remediation, green synthesis and sensors. These enzymes destabilize at extreme pH, elevated temperature or high-organic-content conditions. For these enzymes to find more widespread adoption and use, stabilization in non-native conditions is critical. We report the impact of grafting polymers from the surface of laccase, a metalloenzyme with a Cu active site, modified with a polymerization-initiating species ligated to the protein's lysine residues. Initiators for continuous activator regeneration atom transfer radical polymerization was used to graft a small library of polymers from the protein. The impact of polymer grafting on enzyme activity as a function of pH, temperature or organic solvent was determined. While polymer grafting from laccases was found to increase enzymatic activity, we found that grafting high-molecular-weight dimethylaminoethyl methacrylate displayed the greatest enhancement to catalytic activity. The results demonstrate that polymer grafting can improve laccase activity in native and non-native conditions. (c) 2020 Society of Industrial Chemistry