华盖木多酚氧化酶酶学特性研究

Study on the Enzymology Characteristics of Plyphenol Oxidase from Manglietiastrum sinicum Law.

以华盖木嫁接苗当年生茎段为试材提取PPO酶液,研究温度、pH值、底物邻苯二酚浓度及抑制物对PPO活性的影响。结果表明:华盖木多酚氧化酶的最适温度为35℃,最适pH值为7.0,温度和pH值过高或过低都会降低酶活性;邻苯二酚浓度为0.14 mo.lL-1时,PPO活性最大,低于0.14 mo.lL-1时,随底物浓度的增加,酶活性增加,超过0.14 mol.L-1时,加大底物浓度酶活性降低;Na2SO4、柠檬酸、抗坏血酸(Vc)对华盖木PPO的活性均有一定的抑制效果,其中Vc的抑制效果最显著。

PPO was extracted from the Manglietiastrum sinicum Law grafted plant stem before it was i year old. The influences of different temperature,pH,zymolyte oxopenie acid concentration and stayer on the activity of PPO were studied. The results showed that the optimal temperature was 35℃ and the optimal pH value was 7.0 for plyphenol oxidase from M. sinicum Law; The activi- ty of PPO would reduce because of elevating or reducing temperature or pH. The PPO activity was highest when oxopenie acid concentration was 0.14 mol·L^-1. Under the concentration, the enzyme activity increased with zymolyte concentration increase. Over the concentration, the eneyme activity decreased; Na2SO4, eitrie acid and Ve could suppress the activity of PPO, among them, Vcpossesed the most remarkable controlling effect.