A novel method for the immobilization of tyrosinase to enhance stability

A new method of tyrosinase immobilization by Fuller's-earth adsorption followed by entrapment in gelatin has been developed with 98% activity immobilization yield. An appreciable increase in operational and thermal stability was observed for FEAGE (Fuller's earth-adsorbed gelatin-entrapped) tyrosinase compared with GE (gelatin-entrapped) native enzyme. FEAGE tyrosinase could be used repeatedly after intermittent storage and retained 70% of its initial activity after eight cycles. The half-life of the GE enzyme at 40 degrees C was less than 2 h, whereas the FEAGE enzyme retained about 75% of its initial activity after 2 h. Taken together our data demonstrate clearly that the technique of immobilizing tyrosinase via adsorption followed by entrapment appears promising and is hence recommended for tyrosinase immobilization for commercial production of L-DOPA (3,4-dihydroxyphenylalanine).