PURIFICATION AND CHARACTERIZATION OF OPUNTIA PEROXIDASE

Peroxidase from O puntia ficus indica fruits was purified with chromatographic methods. The enzyme had a characteristic spectrum in the visible region and Rz (A(403)/A(275)) value of 2.56. It showed a single band in SDS-PAGE electrophoresis. The peroxidase had a M(r) of 58000 +/- 2000, an isoelectric point of 7.2 and contained an iron-protoporphyrin IX as prosthetic group. The pH optimum was at 5.75 in 100 mM Na acetate buffer using o-dianisidine as substrate. The activation energy was estimated to be 16 kcal mol(-1) and 50% inactivation occurred after 60 min at 60 degrees.