Matheis G, Belitz H D
Z Lebensm Unters Forsch. 1979 Oct;169(4):271-5. doi: 10.1007/BF01193793.
The soluble phenol oxidase of various potato juices (adjusted from physiological pH to pH 4.5, 7.0 and 7.8) was separated by gel chromatography into multiple molecular forms. In acid or neutral and alkaline potato juices, low-mol.-wt. (less than 150,000 daltons) or high-mol.-wt. (greater than 150,000 daltons) enzyme forms predominate, respectively. Conversion of the low-mol.-wt. enzyme forms into high-mol.-wt. enzyme forms, and vice versa, was achieved by changing the pH values from acidic to neutral or alkaline pH, and vice versa. This substantiated our previous idea that the enzyme multiplicity arises from association of various subunits. In alkaline potato juice, considerable loss of monophenol oxidase activity (assayed at pH 6.0) occurred. This confirmed our previous findings that o-diphenol oxidase is more alkali-stable than monophenol oxidase.
将各种马铃薯汁（从生理pH值调节至pH 4.5、7.0和7.8）中的可溶性酚氧化酶通过凝胶色谱法分离为多种分子形式。在酸性或中性及碱性马铃薯汁中，分别以低分子量（小于150,000道尔顿）或高分子量（大于150,000道尔顿）的酶形式为主。通过将pH值从酸性改变为中性或碱性，反之亦然，可实现低分子量酶形式向高分子量酶形式的转化，反之亦然。这证实了我们之前的观点，即酶的多样性源于各种亚基的缔合。在碱性马铃薯汁中，单酚氧化酶活性（在pH 6.0下测定）出现了相当大的损失。这证实了我们之前的发现，即邻二酚氧化酶比单酚氧化酶更耐碱。
