Direct immobilization of peroxidase on DEAE cellulose from ammonium sulphate fractionated proteins of bitter gourd (Momordica charantia)

The direct immobilization of peroxidases on DEAE cellulose from ammonium sulphate fractionated proteins of bitter gourd has been investigated. The activated DEAE cellulose was quite effective in high yield immobilization of peroxidases from bitter gourd and it could bind nearly 590 enzyme units per g of the matrix. Bitter gourd peroxidase immobilized on this anion exchanger showed very high effectiveness factor ‘η’ as 0.95. BGP bound very strongly to the DEAE cellulose, as it did not detach even in the presence of 0.5 M NaCl. Immobilized bitter gourd peroxidase preparation was more stable to the denaturation induced by pH, heat, urea, proteolytic enzyme, detergents (Surf Excel and Rin powder), Triton X 100 and water-miscible organic solvents (dioxane, dimethyl sulphoxide and n-propanol). Peroxidase adsorbed on the matrix exhibited very high resistance to proteolysis mediated by the trypsin treatment. DEAE cellulose bound bitter gourd peroxidase lost 45% of its initial activity after treatment with 2.5 mg trypsin per ml of incubation mixture for 1 h at 37 °C while the soluble enzyme lost nearly 65% of the initial activity under similar incubation conditions.