Selective Functionalization of Microgels with Enzymes by Sortagging.

Enzyme immobilization has been widely used to improve the stability and recyclability of enzymes in industrial processes. In this work, a sortase-mediated and therefore selective covalent immobilization strategy (sortagging) for enzymes on microgels (GelZyms) was investigated. Aqueous microgels were synthesized of poly (N-vinylcaprolactam)/glycidyl methacrylate (PVCL/GMA) and tagged with the sortase A recognition peptide sequence (LPETG) or its nucleophilic counterpart-tag (GGG). General applicability and selective-immobilization was confirmed by subsequent sortagging of five different enzymes (Bacillus subtilis lipase A (BSLA), Yersinia mollaretii phytase (Ym-phytase), Escherichia coli copper efflux oxidase (CueO laccase), cellulase A2 and Bacillus megaterium monooxygenase P450 BM3). The latter was performed directly from the cell-lysate to ensure cost-effective immobilization. All five immobilized enzymes were catalytically active and could be recycled (e.g. laccase CueO and monooxygenase P450 BM3 F87A; > 55 % residual activity after six cycles). Application potential was demonstrated by using CueO decorated microgels for bleaching of the textile dye indigo carmine.