SUPEROXIDE-DEPENDENT AND ASCORBATE-DEPENDENT FORMATION OF HYDROXYL RADICALS FROM HYDROGEN-PEROXIDE IN THE PRESENCE OF IRON - ARE LACTOFERRIN AND TRANSFERRIN PROMOTERS OF HYDROXYL-RADICAL GENERATION
SUPEROXIDE-DEPENDENT AND ASCORBATE-DEPENDENT FORMATION OF HYDROXYL RADICALS FROM HYDROGEN-PEROXIDE IN THE PRESENCE OF IRON - ARE LACTOFERRIN AND TRANSFERRIN PROMOTERS OF HYDROXYL-RADICAL GENERATION
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DOI：
10.1042/bj2410273
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发表时间：
1987-01-01
影响因子：
4.1
通讯作者：
HALLIWELL, B
中科院分区：
文献类型：
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作者：
ARUOMA, OI;HALLIWELL, B
脱脂乳铁蛋白和脱铁蛋白可防止在pH 7.4的超氧阴离子或抗坏血酸存在下，过氧化氢产生铁离子依赖的羟基自由基(.oh)，无论所需的铁是以离子铁还是以铁蛋白的形式添加。载铁转铁蛋白和乳铁蛋白[2摩尔的铁(III)/摩尔]没有显示出保护能力，但它们本身不会加速.OH的产生，除非反应混合物中存在螯合剂，特别是当蛋白质错误地负载铁的时候。在酸性pH值下，脱辅基蛋白的保护能力减弱，完全载铁的蛋白可以释放一些铁，从而能够加速.OH的生成。讨论了这些观测的生理学意义。
Apo-lactoferrin and apo-transferrin protect against iron-ion-dependent hydroxyl-radical (.OH) generation from H2O2 in the presence of superoxide radicals or ascorbic acid at pH 7.4, whether the necessary iron is added as ionic iron or as ferritin. Iron-loaded transferrin and lactoferrin [2 mol of Fe(III)/mol] show no protective ability, but do not themselves accelerate .OH production unless chelating agents are present in the reaction mixture, especially if the proteins are incorrectly loaded with iron. At acidic pH values, the protective ability of the apoproteins is diminished, and the fully iron-loaded proteins can release some iron in a form able to accelerate .OH generation. The physiological significance of these observations is discussed.