Stabilization of DEAE cellulose adsorbed and glutaraldehyde crosslinkedwhite radish (Raphanus sativus) peroxidase

Abstract

Present work demonstrates adsorption of ammonium sulphate fractionated proteins of white radish (Raphanus sativus) onDEAE cellulose and its crosslinking by glutaraldehyde. Adsorbed enzyme exhibited an immobilization yield of 88% and itsactivity decreased to 81% after crosslinking. Temperature and pH optima for soluble and immobilized enzyme were same. Therewas a significant enhancement in activity of adsorbed and crosslinked peroxidase to 136%, 143%, and 126% after its exposure60% dimethylformamide, 60% n-propanol and 60% acetone, respectively. However, soluble enzyme under similar experimental conditions, exhibited only 60%, 35% and 16% activity, respectively. Soluble enzyme lost 27% activity after its exposure to 4.0urea for 1 h, whereas activity of adsorbed crosslinked and uncrosslinked enzyme was enhanced to 153% and 142%,respectively. Adsorbed and crosslinked peroxidase retained 63% activity after 1 h exposure to 1.0 M sodium sulphite, whereasonly adsorbed and soluble enzyme lost 74% and 97% of their initial activity. Adsorbed and crosslinked enzyme retained 61% ofactivity after 7th repeated use as compared to adsorbed enzyme, which retained a marginal activity of 21%.