1,4-苯醌作为单胺氧化酶的新型抑制剂。

1,4-Benzoquinone as a new inhibitor of monoamine oxidase.

作者信息

Naoi M, Nomura Y, Ishiki R, Suzuki H, Nagatsu T

出版信息

Neurosci Lett. 1987 Jun 15;77(2):215-20. doi: 10.1016/0304-3940(87)90589-1.

Abstract

The effect of 1,4-benzoquinone (BQ) on type A and B monoamine oxidase (MAO-A and -B) in human brain synaptosomes was examined. MAO-A was found to be markedly inhibited by BQ competitively with the substrate, kynuramine, while MAO-B was less sensitive to this inhibitor and the inhibition was non-competitive with the substrate. The Ki value of MAO-A (9.62 +/- 0.35 microM) was much smaller than the Km value of the enzyme with the substrate (56.3 +/- 3.5 microM) or the Ki value of MAO-B with BQ (20.3 +/- 0.9 microM). The inhibition of MAO-A by BQ was also confirmed by the use of platelet mitochondria and clonal rat pheochromocytoma PC12h cells as enzyme sources. The inhibition of MAO activity by BQ proved to be reversible: the inhibited enzyme activity could be recovered by column chromatography on Sephadex G-25.

摘要

研究了1,4-苯醌（BQ）对人脑海突触体中A型和B型单胺氧化酶（MAO-A和MAO-B）的作用。发现MAO-A被BQ与底物犬尿胺竞争性地显著抑制，而MAO-B对该抑制剂不太敏感，且抑制作用与底物非竞争性。MAO-A的Ki值（9.62±0.35微摩尔）远小于该酶与底物的Km值（56.3±3.5微摩尔）或MAO-B与BQ的Ki值（20.3±0.9微摩尔）。通过使用血小板线粒体和克隆大鼠嗜铬细胞瘤PC12h细胞作为酶源，也证实了BQ对MAO-A的抑制作用。BQ对MAO活性的抑制被证明是可逆的：被抑制的酶活性可通过在Sephadex G-25上进行柱色谱法恢复。