We report the synthesis of new polymer-protein conjugates using a grafting-from method employing photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. Lipase, an industrially important enzyme, was modified with a reversible addition-fragmentation (RAFT) chain transfer agent (CTA) using activated ester chemistry. To study the effects of polymer composition and molecular weight on the enzyme activity, a hydrophilic and hydrophobic polymer were grafted at three different polymer lengths. We found a significant impact of polymer composition on enzyme activity with hydrophobic polymer substantially increasing enzyme activity. (C) 2018 Elsevier Ltd. All rights reserved.