THE THERMOSTABILITY OF PURIFIED MANGO ISOPEROXIDASES

Small amounts of purified mango (var. Chaunsa) anionic and cationic isoperoxidases have been obtained by ion-exchange chromatography. It has been shown that peroxidase activity present in crude extracts of mango pulp is less stable to heat than the enzymic activity of highly purified individual mango isoperoxidases. For the purified isoperoxidases heat-inactivation is still non-linear. It is suggested that this may be due to microheterogeneity in covalently bound oligosaccharide residues at the molecular level. Isoperoxidase activity did not regenerate after heat treatment of crude mango extracts or purified isoenzymes.