alpha-Amylase enzyme was adsorbed on poly(N-vinyl 2-pyrrolidone/itaconic ac
id) (P(VP/IA)) hydrogels prepared by irradiating the ternary mixtures of VP
/IA/water by gamma-rays at ambient temperature. The adsorption capacity of
the hydrogels was determined to increase from 2.30 to 3.40 mg alpha-amylase
/g dry gel with increasing amount of IA in gel system. Kinetic parameters w
ere calculated as 2.51 g/dm(3) for K-m and 1.67 x 10(-3) g/dm(3) mill for V
-max for free enzyme and in the range of 3.88-5.02 g/dm(3) for K-m and 1.62
x 10(-3) - 2.27 x 10(-3) g/dm(3) min for V-max depending on the amount of
IA in the hydrogel. Enzyme activities were found to increase from 49.9% to
77.4% with increasing amount of IA in the gel system and retained their act
ivities for one month storage. On the other hand, the free enzyme loses its
activity completely after 20 days. (C) 1999 Elsevier Science B.V. All righ
ts reserved.