Oxygen-based free radical generation by ferrous ions and deferoxamine.
Oxygen-based free radical generation by ferrous ions and deferoxamine.
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DOI：
10.1016/s0021-9258(19)47178-0
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发表时间：
1989-11
期刊：
影响因子：
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通讯作者：
S. Klebanoff;A. Waltersdorph;B. R. Michel;H. Rosen
中科院分区：
文献类型：
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作者：
S. Klebanoff;A. Waltersdorph;B. R. Michel;H. Rosen
去铁胺加速铁的自氧化，通过快速消失的Fe2+，相关的Fe3+的出现和氧气的摄取来测量。质子在反应中被释放。通过辣根过氧化物酶催化东scopoltin氧化反应检测h2o2的生成，通过自旋捕集器5,5-二甲基-1-吡咯啉-氧化物（DMPO）与OH·自旋捕集器（DMPO/OH）·的形成和二甲基亚砜进一步加成生成甲基自由基加合物（OH·）推测OH·的生成。过氧化氢酶能抑制（DMPO/OH）·加合物的形成，而超氧化物歧化酶不能。氧化剂将碘化物转化为三氯乙酸可沉淀的形式（碘化），并对对数相大肠杆菌具有杀菌作用。过氧化氢酶和OH·清除剂对碘化和杀菌活性均有抑制作用，而超氧化物歧化酶对碘化和杀菌活性无抑制作用。在5 × 10-4M醋酸缓冲液中，pH为5.0，Fe2+和去铁胺浓度在10-4M等摩尔时，碘化效果最佳。Fe2+不能被Fe3+、Co2+、Zn2+、Ca2+、Mg2+、Mn2+取代，去铁胺不能被EDTA、二乙烯三胺五乙酸、邻苯二酚替代。这些结果表明，铁离子和去铁胺可以作为氧自由基生成系统，这可能有助于其在体外和体内的生物效应。
Deferoxamine accelerates the autooxidation of iron as measured by the rapid disappearance of Fe2+, the associated appearance of Fe3+, and the uptake of oxygen. Protons are released in the reaction. The formation of H2O2was detected by the horseradish peroxidase-catalyzed oxidation of scopoletin, and the formation of hydroxyl radicals (OH·) was suggested by the formation of the OH·spin trap adduct (DMPO/OH)·with the spin trap 5,5-dimethyl-1-pyrrolineN-oxide (DMPO) and the generation of the methyl radical adduct on the further addition of dimethyl sulfoxide. (DMPO/OH)·adduct formation was inhibited by catalase but not by superoxide dismutase. The oxidant formed converted iodide to a trichloroacetic acid-precipitable form (iodination) and was bactericidal to logarithmic phaseEscherichia coli. Both iodination and bactericidal activity was inhibited by catalase and by OH·scavengers, but not by superoxide dismutase. Iodination was optimal in 5 × 10-4M acetate buffer, pH 5.0, and when the Fe2+and deferoxamine concentrations were equimolar at 10-4M. Fe2+could not be replaced by Fe3+, Co2+, Zn2+, Ca2+, Mg2+, or Mn2+, or deferoxamine by EDTA, diethylenetriaminepentaacetic acid, or bathophenanthroline. These findings indicate that Fe2+and deferoxamine can act as an oxygen radical generating system, which may contribute to its biological effectsin vitroandin vivo.