Catalytic activity and the stability of horseradish peroxidase increase as a result of its incorporation into a polyelectrolyte complex with chitosan

• Published in: Applied biochemistry and microbiology 2009-03, Vol.45 (2), p.125-129
• Main Authors: Veselova, I. A, Kireiko, A. V, Shekhovtsova, T. N
• Format: Article
• Language: English
• Subjects: Biochemistry; Biomedical and Life Sciences; Catalysis; Enzymes; Hydrogen peroxide; Life Sciences; Medical Microbiology; Microbiology; Substrates
• ISSN: 0003-6838; 1608-3024
• DOI: 10.1134/S0003683809020021

The incorporation of horseradish peroxidase into polyelectrolyte complexes with chitosans of different molecular weights (MW 5-150 kDa) yielded highly active and stable enzyme preparations. As a result of the selection of optimal conditions for the formation of peroxidase-chitosan complexes, it was found that 0.1% chitosan with a MW of 10 kDa had the strongest activatory effect on peroxidase (activation degree, >70%) in the reaction of o-dianisidine oxidation by hydrogen peroxide. The complex formed by 0.001% chitosan with a molecular weight of 150 kDa was most stable: when immobilized on foamed polyurethane, it retained at least 50% of the initial activity for 550 days. The highest catalytic activity was exhibited in a 0.05 M phthalate buffer (pH 5.9-6.2) by the complex containing 0.006-0.009% chitosan in the indicator reaction. The activatory effect of the polysaccharide on the enzyme was determined by its influence on the binding and conversion of the reducting substrate peroxidase.