Trypsin Immobilization on Poly(N-Vinylcaprolactam) and Its Copolymers with N-Vinylimidazole

Poly(N-vinylcaprolactam) and its copolymers with N-vinylimidazole were studied as carriers for trypsin immobilization. Trypsin immobilization on poly(N-vinylcaprolactam) was shown to have practically no effect on the esterase activity of the enzyme while the formation of trypsin associates with copolymers of N-vinylcaprolactam and N-vinylimidazole led to increased catalytic capacity of the enzyme by 39, 26, and 31% with vinylcaprolactam contents in the carrier of 47, 64, and 79%, respectively. IR spectroscopy was used to reveal the mechanism of the interaction between trypsin and the polymers. Hydrogen bonds and hydrophobic interactions were shown to contribute most to the formation of carrier(enzyme associates. These results highlight the use of smart polymers as a matrix for immobilization of biologically active substances.