Characterization of free and immobilized amine oxidase

Bovine plasma amine oxidase was covalently bound to CH-Sepharose 4B by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The immobilized enzyme showed no significant change in specific activity when spermidine was the substrate, while the enzyme affinity toward benzylamine and propylamine increased significantly. Similarly, the pig kidney diamine oxidase physically adsorbed to Con A-Sepharose showed large changes in affinity toward substrates such as p-dimethylaminoethylbenzylamine with respect to the native enzyme. These changes are discussed in terms of active site modification as a consequence of the enzyme immobilization.