Shumilla J A, Wetterhahn K E, Barchowsky A
Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755-3835, USA.
Arch Biochem Biophys. 1998 Jan 15;349(2):356-62. doi: 10.1006/abbi.1997.0470.
NF-kappa B binding to DNA in the presence of thiol-reactive metals has been explored in vitro. Gel mobility shift assays using total nuclear extracts isolated from tumor necrosis factor alpha-treated A549 cells demonstrated dose-dependent inhibition of NF-kappa B binding by chromium, cadmium, mercury, zinc, and arsenite. Maximum inhibition of binding occurred when these metals were preincubated with the nuclear proteins prior to addition of radiolabeled oligonucleotide. The potency of mercury, cadmium, and zinc for inhibiting binding closely correlated to the affinity of these metals for protein thiols. Further addition of dithiothreitol competitively blocked the effects of all of the metals, except chromium(III), on NF-kappa B binding. This study demonstrates mechanisms for metals to inhibit NF-kappa B-DNA binding through interactions with critical protein sulfhydryls.
已在体外研究了硫醇反应性金属存在下NF-κB与DNA的结合。使用从肿瘤坏死因子α处理的A549细胞中分离的总核提取物进行的凝胶迁移率变动分析表明，铬、镉、汞、锌和亚砷酸盐对NF-κB结合具有剂量依赖性抑制作用。当在添加放射性标记的寡核苷酸之前将这些金属与核蛋白预孵育时，结合的抑制作用最大。汞、镉和锌抑制结合的效力与这些金属对蛋白质硫醇的亲和力密切相关。进一步添加二硫苏糖醇竞争性地阻断了除铬（III）以外的所有金属对NF-κB结合的影响。这项研究证明了金属通过与关键蛋白质巯基相互作用来抑制NF-κB-DNA结合的机制。
