Immobilization of trypsin on an enteric polymer Eudragit S-100 for the biocatalysis of macromolecular substrate

Trypsin was covalently linked to Eudragit S-100 tan enteric coating polymer) by carbodiimide coupling method. Nearly 90% of enzyme activity was conjugated to the polymer whereas actual observed (expressed) activity was 64%. The enzyme bound to the polymer by simple adsorption as well but leached off the polymer in the presence of high ionic strength (1.0 M NaCl). The immobilized enzyme showed stability to autolysis at 45 degrees C and had a marginal shift in pH optimum. The K-m value of the enzyme decreased from 1.0 x 10(-3) M to 0.7 x 10-3 M on immobilization. The soluble Eudragit-trypsin conjugate was used to hydrolyze casein at 45 degrees C. Eudragit being a reversibly soluble-insoluble polymer, the biocatalyst could be recovered and reused. (C) 1998 Elsevier Science B.V. All rights reserved.