Polyphenoloxidase from the peel of the mango fruit (Mangifera indica).

Polyphenoloxidase isolated from the mango fruit peel in (i) preclimacteric and (ii) climacteric stages was purified 50-fold by alcohol precipation and DEAE cellulose column. Of the 6 substrates studied the enzymes both in (i) and (ii) stages showed max. activity towards catechol and 4-methyl catechol. Cu restored the enzyme activity lost by dialysis against 1 mM sodium cyanide. Copper chelating compounds (sodium azide and sodiumdiethyl dithiocarbamate) inhibited the enzyme activity. The pH optima for enzyme activity was 5.4.