Kovacs Julie A, Brines Lisa M
The Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, USA.
Acc Chem Res. 2007 Jul;40(7):501-9. doi: 10.1021/ar600059h. Epub 2007 May 31.
Toxic superoxide radicals, generated via adventitious reduction of dioxygen, have been implicated in a number of disease states. The cysteinate-ligated non-heme iron enzyme superoxide reductase (SOR) degrades superoxide via reduction. Biomimetic analogues which provide insight into why nature utilizes a trans-thiolate to promote SOR function are described. Spectroscopic and/or structural characterization of the first examples of thiolate-ligated Fe (III)-peroxo complexes provides important benchmark parameters for the identification of biological intermediates. Oxidative addition of superoxide is favored by low redox potentials. The trans influence of the thiolate appears to significantly weaken the Fe-O peroxo bond, favoring proton-induced release of H 2O 2 from a high-spin Fe(III)-OOH complex.
通过氧气的偶然还原产生的有毒超氧自由基与多种疾病状态有关。半胱氨酸连接的非血红素铁酶超氧化物还原酶(SOR)通过还原作用降解超氧化物。本文描述了一些仿生类似物,这些类似物有助于深入了解自然界为何利用反式硫醇盐来促进SOR的功能。硫醇盐连接的Fe(III)-过氧配合物的首个实例的光谱和/或结构表征为生物中间体的鉴定提供了重要的基准参数。低氧化还原电位有利于超氧化物的氧化加成。硫醇盐的反式影响似乎显著削弱了Fe-O过氧键,有利于质子诱导高自旋Fe(III)-OOH配合物释放H2O2。