一氧化二氮对植物和动物细胞色素氧化酶的抑制作用与细胞色素c浓度的关系。

Inhibition of plant and animal cytochrome oxidases by nitrous oxide as a function of cytochrome c concentration.

作者信息

Chervin C, Thibaud M C

机构信息

Département de Physiologie Végétale et Ecosystèmes, Centre d'Etudes de Cadarache, Saint-Paul-lez-Durance, France.

出版信息

Biochimie. 1992 Dec;74(12):1125-7. doi: 10.1016/0300-9084(92)90012-4.

DOI:10.1016/0300-9084(92)90012-4

PMID:1337983

Abstract

Cytochrome oxidase from both pea leaves and bovine heart shows lower activity under a mixture of 79% N2O/21% O2 than under ambient air. This inhibition is not detectable below 5 microM cytochrome c but appears with increasing concentrations of cytochrome c. These results suggest that the N2O-induced inhibition of cytochrome c oxidase is modulated by cytochrome c concentration. This seems to concern only the lowest affinity site of the oxidase. Apparently, N2O and cytochrome c do not share the same site of fixation on the oxidase.

摘要

豌豆叶片和牛心的细胞色素氧化酶在79% N₂O/21% O₂的混合气体中比在环境空气中表现出更低的活性。在细胞色素c浓度低于5微摩尔时，这种抑制作用无法检测到，但随着细胞色素c浓度的增加而出现。这些结果表明，N₂O诱导的细胞色素c氧化酶抑制作用受细胞色素c浓度的调节。这似乎只涉及氧化酶的最低亲和力位点。显然，N₂O和细胞色素c在氧化酶上的固定位点不同。