Dramatic Increase in Catalytic Performance of Immobilized Lipases by Their Stabilization on Polymer Brush Supports

Despite their widespread use in biocatalysis, the marginal stability of lipases can significantly limit their catalytic performance in industrial biotransformations. Here, we demonstrate that this limitation can be overcome by immobilization on poly­(sulfobetaine methacrylate) (PSBMA) polymer brushes. Specifically, the immobilization of Bacillus subtilis lipase A (lipA) on PSBMA brushes resulted in a 100-fold enhancement in turnover frequency relative to ambient conditions at the temperature optimum of the immobilized enzyme, which was also improved by immobilization. This significant enhancement in catalytic performance was due to the structural stabilization of lipA as well as changes in lipA conformational dynamics as measured using single-molecule Förster resonance energy transfer. Interestingly, the enhancement in catalytic performance of lipases depended strongly on the chemistry of the brush. These findings demonstrate that tuning the brush chemistry can lead to marked improvements in the catalytic efficiency of immobilized lipases, which may have major ramifications in industrial biocatalysis