ONE-STEP PURIFICATION OF AN AVOCADO PEROXIDASE

A rapid isolation procedure was developed for purification of a soluble anionic isoperoxidase (donor: hydrogen peroxide oxidoreductase, EC 1.11.1.7) from avocado (Persea americana, M. cv. Topa Topa) leaves. Electroelution from a native polyacrylamide gel, was the only requirement to achieve this. The purified isoperoxidase was a monomer, 60 kDa molecular mass, with a carbohydrate moiety. The amino acid composition showed 358 amino acid residues and appeared to be similar to those reported in other plant peroxidases. The study of some enzymatic properties, e. g. substrate specificity, susceptibility to effecters and so on, revealed that this isoperoxidase follows, in general, the action patterns previously established for anionic isoperoxidases.