Abstract
In the previous report (1) it has been demonstrated that hydrogen or electron from reduced amine oxidase is transferred not only to molecular oxygen but also to cytochrome c in the oxidation process of histamine and some other biological amines. It has also been shown that although ethylenediamine is generally considered not to be qualified as the substrate of amine oxidizing enzyme, it can serve as a hydrogen donor and induces the cytochrome c reduction under both aerobic and anaerobic conditions. Hill et al. (2) reported that ethylenediamine does not serve as the substrate for amine oxidase from pea seedlings. However, they found that when the enzyme is incubated with ethylenediamine under anaerobic conditions, there occur changes in the absorption spectrum. These changes were not restored by oxygenation unlike in the case of other substrates such as putrescine. The present paper describes the result of kinetic and stoichiometric studies on the reduction of cytochrome c induced by ethylenediamine, using amine oxidase from Aspergillus niger purified by Yamada et al. (3). A preliminary short communication of this paper has been published earlier (10).
