purification and partial characterization o f peroxidases from cultivated raphanus sativus l. var. cicil

two peroxidases (ec. 1.11.1.7), pod i and pod ii were purified from the roots of cultivatedraphanus sativus l. var. cicil by one step ion-exchange chromatography after fractionation by acetone. the molecular weight of these enzymes were 43000 and 41000 daltons and rz 1.2 and 2.0 for pod i and pod ii, respectively. both enzymes consisted of a single polypeptide chain on sds-page. the maximum activity of pod i was observed at ph 4.6 and 30°c and for pod ii, at ph 6.5 and 60°c. the km value of pod i for h202 was 7.26 mm and for pod ii, 2 mm toward o-dianisidin. both isoenzymes were stable for 48 hours in temperatures up to 40°c and stable in ph 4-8 for 3 hours.