Tea Leaf Polyphenol Oxidase

A remarkable increase in polyphenol oxidase activity was observed in tea leaves after plucking. When the tea leaves treated with the specific inhibitors for the protein biosynthesis such as blasticidin S and puromycin A by the absorption through stem or by the vacuum infiltration, the increase in the enzyme activity was severely prevented. Therefore, it was thought that these antibiotics inhibited the activation of polyphenol oxidase. In addition, CM-cellulose column chromatogram of the enzyme protein of the withered leaves was different from that of the fresh leaves. It was also considered that new protein containing the enzyme activity developed in the withered leaves.

These results suggest that the synthesis of the enzyme protein occurred in tea leaves after plucking.