某些黄素酶通过超氧化物介导铁从铁蛋白中释放出来。

Superoxide-mediated release of iron from ferritin by some flavoenzymes.

作者信息

Bando Y, Aki K

机构信息

Institute for Enzyme Research, University of Tokushima, Japan.

出版信息

Biochem Biophys Res Commun. 1990 Apr 30;168(2):389-95. doi: 10.1016/0006-291x(90)92333-u.

DOI:10.1016/0006-291x(90)92333-u

PMID:2159290

Abstract

NADH-lipoamide dehydrogenase mobilized iron from ferritin under aerobic conditions. Superoxide dismutase strongly inhibited this mobilization, indicating that the superoxide radical is generated by the enzymatic reaction and release iron from ferritin. Addition of lipoamide as an electron acceptor to NADH-lipoamide dehydrogenase increased the release of iron from ferritin and this release was partially inhibited by superoxide dismutase. Similarly, addition of menadione (2-methyl-1, 4-naphthoquinone) as an electron acceptor to xanthine-xanthine oxidase promoted the release of iron from ferritin and this release was strongly inhibited by superoxide dismutase. These results suggest that dihydrolipoamide and semiquinone of menadione can react with oxygen to form the superoxide radical that mediates release of iron from ferritin.

摘要

在有氧条件下，NADH-硫辛酰胺脱氢酶从铁蛋白中动员铁。超氧化物歧化酶强烈抑制这种动员，表明超氧阴离子是由酶促反应产生并从铁蛋白中释放铁。向NADH-硫辛酰胺脱氢酶中添加硫辛酰胺作为电子受体增加了铁从铁蛋白中的释放，并且这种释放被超氧化物歧化酶部分抑制。同样，向黄嘌呤-黄嘌呤氧化酶中添加甲萘醌（2-甲基-1,4-萘醌）作为电子受体促进了铁从铁蛋白中的释放，并且这种释放被超氧化物歧化酶强烈抑制。这些结果表明，硫辛酰胺二氢化物和甲萘醌半醌可以与氧反应形成介导铁从铁蛋白中释放的超氧阴离子。