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°C, but the activity was almost completely lost at 60°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.