Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street, Houston, Texas 77251, USA.
J Am Chem Soc. 2009 Nov 18;131(45):16371-3. doi: 10.1021/ja9058266.
The mechanism by which the human copper (Cu) chaperone Atox1 delivers Cu to metal-binding domains of Wilson disease (WD) protein for insertion into cuproenzymes is unclear. Using near-UV circular dichroism as a new tool to probe chaperone-target interactions, in combination with gel filtration and molecular dynamics simulations, we here demonstrate that Atox1 forms a stable Cu-dependent adduct with the fourth metal-binding domain of WD (WD4). Using point-mutated Atox1 variants, we show that the adduct forms in the absence of conserved residues M10 or T11 but K60 is essential for heterocomplex formation and Cu transfer. Dissection of heterocomplex energetic components reveals a crucial role for K60-mediated electrostatic interaction.
人铜 (Cu) 伴侣蛋白 Atox1 将 Cu 递送至威尔逊病 (WD) 蛋白的金属结合域以插入铜酶的机制尚不清楚。使用近紫外圆二色性作为探测伴侣蛋白-靶标相互作用的新工具，结合凝胶过滤和分子动力学模拟，我们在此证明 Atox1 与 WD 的第四个金属结合域 (WD4) 形成稳定的 Cu 依赖性加合物。使用点突变的 Atox1 变体，我们表明该加合物在没有保守残基 M10 或 T11 的情况下形成，但 K60 对于异源复合物形成和 Cu 转移是必需的。异源复合物能量成分的剖析揭示了 K60 介导的静电相互作用的关键作用。
