Immobilization of α‐chymotrypsin on poly(methyl methacrylate‐co‐acrylic acid) core‐shell latex

Core‐shell latex of poly(methyl methacrylate‐co‐acrylic acid) with surface containing functional carboxylic acids, was prepared by seed polymerization and characterized. α‐Chymotrypsin was immobilized on the surface of these latex particles by chemical bonding in aqueous medium, using a water soluble carbodiimide as coupling agent. The latex particles size before and after the attachment of the enzyme was determined using photon correlation spectroscopy. The activities of free and immobilized enzyme were studied as a function of temperature, reusability and pH. The activity for the immobilized enzyme was highest at a pH slightly higher than the optimum pH of free enzyme, which could be explained due to the polyanionic matrix as well as due to the variation in the size of latex at higher pH, which provided more mobility to the enzyme, and thus a higher activity.