Pérez-Gilabert M, García Carmona F
Departamento de Bioquímica y Biología Molecular-A, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, E-30071 Murcia, Spain.
J Agric Food Chem. 2000 Mar;48(3):695-700. doi: 10.1021/jf990292r.
In the present paper the catecholase and cresolase activities of eggplant polyphenol oxidase (PPO) are described. To preserve the latter activity, a partially purified enzyme was used. Peroxidase was removed from the preparation to avoid its interference with PPO during phenol oxidation. The partially purified eggplant PPO was fully active. The catecholase/cresolase ratio of 41.1 indicated that, in a pH close to the physiological, diphenol oxidation predominates over monophenol oxidation. The characteristic lag phase of the cresolase activity is modulated by the pH, the monophenol and diphenol concentrations, and the enzyme's concentration. The effect of several inhibitors was also tested, and the K(i) values of the two most effective (tropolone and 4-hexylresorcinol) were determined.
本文描述了茄子多酚氧化酶（PPO）的儿茶酚酶和甲酚酶活性。为保留后者的活性，使用了部分纯化的酶。从制剂中去除了过氧化物酶，以避免其在酚氧化过程中干扰PPO。部分纯化的茄子PPO具有完全活性。41.1的儿茶酚酶/甲酚酶比率表明，在接近生理pH值时，二酚氧化比单酚氧化占优势。甲酚酶活性的特征性滞后阶段受pH值、单酚和二酚浓度以及酶浓度的调节。还测试了几种抑制剂的作用，并测定了两种最有效抑制剂（托酚酮和4-己基间苯二酚）的K(i)值。
