A CO-binding hemoprotein derived from Tetrahymena pyriformis.

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    • SASAKI Kazuyuki
    • Department of Biology, Faculty of Science, Osaka University|Department of Nutrition and Physiological Chemistry, The School of Medicine, Osaka University
    • SHIBASAKA Mineo
    • Department of Biology, Faculty of Science, Osaka University|Laboratory for Plant Ecolgical Studies, Faculty of Science, Kyoto University


A CO-binding hemoprotein was purified from <i>Tetrahymena pyriformis</i> and some of its properties were studied.<br> The hemoprotein possessed protoheme, its molecular weight was about 11, 000, and its isoelectric point was at pH 8.2. The oxidized form of the hemoprotein showed the Soret band at 406nm and had no distinct peaks in the region of α- and β-bands, while the reduced form showed the peaks at 426, 527 and 560nm. The hemoprotein reacted with CO resulting in shift of the Soret band from 426 to 420nm. The CO-compound showed a broad band from 537 to 573nm. The hemoprotein was not autoxidizable or oxygenated either. It did not show either of the cytochrome oxidase, peroxidase and NADH oxidase activities.<br> It should be carefully determined whether or not cytochrome <i>o</i> is functioning as the terminal oxidase in <i>T. pyriformis</i>, as the CO-binding hemoprotein which does not react with molecular oxygen exists in the organism.


  • Agricultural and Biological Chemistry

    Agricultural and Biological Chemistry 42(10), 1861-1865, 1978

    Japan Society for Bioscience, Biotechnology, and Agrochemistry


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