Molecularly imprinted polymer mimics of chymotrypsin: 2. Functional monomers and hydrolytic activity

Abstract

Various polymers mimicking hydrolytic activity of chymotrypsin were synthesized by grafting Co(II) coordinated monomer-template assemblies of different monomers bearing hydroxyl, carboxyl and imidazole groups on microporous support poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly(GMA-EGDMA)). All mimics were hydrolytically active against "chymotrypsin specific" substrate N-benzyloxycarbonyl tyrosyl para nitro phenyl ester. The catalytic activity of the mimic increased with the nucleophilicity of the functional monomer representing serine hydroxyl, and was further enhanced by the cooperative effect of the carboxyl group. With decrease in surface area of the carrier support poly(GMA-EGDMA), the K_m value of mimics increased, indicating restricted accessibility of substrate towards the functional groups present on the support. For a series of mimics containing the same functional monomers, the surface area of the support decreased with increased levels of grafting, which led to both higher k_cat and K_m. These trends are consistent with those reported for reactions of immobilized enzymes.