Partial Purification and Characterization of Polyphenol Oxidase Isozymes in Banana Bud.
Polyphenol oxidase was extracted from banana buds in the presences of Triton X-100, isoascorbate, and Polyclar AT, and two isozymes I and II have been separated and partially purified by chromatographies on Butyl Toyopearl 650 and DEAE-cellulose. I and II had different mobility in polyacrylamide gel electrophoresis with optimum pHs of 6.8 and 5.5, respectively. Both enzymes showed the apparent Km values of 0.5 mM for dopamine with substrate inhibitions at its higher concentrations. I and II were inhibited competitively by NaCI with the Ki values of 140 mM and 40 mM, respectively. I and II have a high heat stability, and 88 and 95% of the initial activities were retained after 1-hr incubation at 70°C, respectively.
a Faculty of Domestic Science , Nagoya Women's University , 3-40, Shioji, Mizuho , Nagoya 467 , Japan.
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a Faculty of Domestic Science , Nagoya Women's University , 3-40, Shioji, Mizuho , Nagoya 467 , Japan.|b Koryo International College , Sagamine, Nissin, Aichi-gun , Aichi 470-01 , Japan.
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Iwatsuki
a Faculty of Domestic Science , Nagoya Women's University , 3-40, Shioji, Mizuho , Nagoya 467 , Japan.
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Uritani
a Faculty of Domestic Science , Nagoya Women's University , 3-40, Shioji, Mizuho , Nagoya 467 , Japan.|c Institute of Food Science and Technology, the University of the Philippines at Los Banos, College , Laguna 4031 , Philippines.
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Alvarez
a Faculty of Domestic Science , Nagoya Women's University , 3-40, Shioji, Mizuho , Nagoya 467 , Japan.|c Institute of Food Science and Technology, the University of the Philippines at Los Banos, College , Laguna 4031 , Philippines.
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Garcia