CHARACTERIZATION OF CATALASE FROM THE SEAWEED PORPHYRA-YEZOENSIS

Catalase was partially purified from the marine red macroalga Porphyra yezoensis by sequential ammonium sulfate fractionation, ion-exchange and hydrophobic interaction chromatography. Extraction from frozen and powdered material under liquid nitrogen was more efficient than that from fresh or freeze-dried material. The maximal activity of the enzyme was observed in the pH range 6.0-11.0, but the activity rapidly decreased below pH 6.0. The enzyme had an optimum reaction temperature at 30 degrees C, but the activity was almost completely lost at 60 degrees C. Heme-catalase inhibitors, such as hydroxylamine, azide and cyanide, inhibited the enzyme activity markedly. The enzyme was also inactivated by both dithiothreitol and 2-mercaptoethanol.