NONCOVALENT IMMOBILIZATION OF POTATO (SOLANUM-TUBEROSUM) POLYPHENOL OXIDASE ON CHITIN

A partially purified polyphenol oxidase (tyrosinase) from potato (Sola num tuberosum) was immobilized on chitin by simple adsorption at pH 6. 8. The activity retained by the immobilized enzyme was as high as 95%. No drastic changes were observed in properties, such as K-m, V-max. a nd thermal stability, as a result of the immobilization. The enzyme ac tivity did not leach upon washing with 1 M NaCl or pH 5.0 buffer. Both native as well as immobilized enzyme showed enhancement of activity w hen acetonitrile was used as a co-solvent in the reaction medium. The relative activity in both cases varied with the percentage of acetonit rile used.