猪血浆苄胺氧化酶：关于反应机制的一些思考。

Pig plasma benzylamine oxidase: some considerations on the mechanism of the reaction.

作者信息

Buffoni F, Ignesti G, Coppi C

出版信息

Ital J Biochem. 1977 Mar-Apr;26(2):111-21.

Abstract

The kinetics of benzaldehyde formation during the oxidation of benzylamine by pig plasma benzylamine oxidase have been studied at different pH values. It has been shown that the first step of the reaction catalyzed by this enzyme is the formation of a Schiff base between the amino group of the substrate and the aldehyde group of the enzyme. Present kinetic studies are consistent with this mechanism and demonstrate the existence of two steps which are alternatively rate-limiting one below pH 6.0, the other above this pH value. The rate-limiting step above pH 6.0 requires the participation of OH-. A mechanism of reaction has been proposed in which the release of products follows the sequence: hydrogen peroxide, aldehyde, ammonia.

摘要

在不同pH值下，研究了猪血浆苄胺氧化酶催化苄胺氧化过程中苯甲醛形成的动力学。结果表明，该酶催化反应的第一步是底物的氨基与酶的醛基之间形成席夫碱。目前的动力学研究与该机制一致，并证明存在两个步骤，在pH 6.0以下，其中一个步骤交替成为限速步骤；在该pH值以上，另一个步骤成为限速步骤。pH 6.0以上的限速步骤需要OH-的参与。已提出一种反应机制，其中产物的释放顺序为：过氧化氢、醛、氨。