山药多酚氧化酶特性研究

Properties of Polyphenol Oxidase from Yam

以邻苯二酚为底物,采用分光光度法测定波长410nm处山药多酚氧化酶的活性,研究了pH、温度、底物浓度和抑制剂对山药多酚氧化酶活性的影响。结果表明,山药多酚氧化酶的最适反应pH=6·0,最适反应温度为35℃;化学抑制剂柠檬酸、苹果酸、L-抗坏血酸对多酚氧化酶均有抑制作用,L-抗坏血酸抑制作用最为明显,L-抗坏血酸抑制机理为反竞争性抑制。

The yam polyphenol oxidase activity was determined spectrophotometrically at 410 nm with catechol as substrate,and effect of different pH,temperature,substrate concentration and inhibitor concentration on polyphenol oxidase activity was studied.The results showed that the optimum pH and temperature was 6.0 and 35 ℃ respectively.L-ascorbic acid,critic acid and malic acid all inhibited yam polyphenol oxidase activity.Among them the action of L-ascorbic acid was most significant,and the mechanism was anti competitive inhibition.