Copper-induced conformational changes in the N-terminal domain of the Wilson disease copper-transporting ATPase
Copper-induced conformational changes in the N-terminal domain of the Wilson disease copper-transporting ATPase
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DOI：
10.1021/bi992222j
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发表时间：
2000-02-22
期刊：
影响因子：
2.9
通讯作者：
Sarkar, B
中科院分区：
文献类型：
--
作者：
DiDonato, M;Hsu, HF;Sarkar, B
肝豆状核变性铜转运ATP酶在铜的细胞内运输中起着关键作用。这种蛋白质的突变导致铜在肝脏、肾脏和大脑中积累到毒性水平，随后导致广泛的组织损伤和死亡。ATP酶有一个新的氨基末端结构域（类似于70 kDa），其中包含6个重复的铜结合基序GMTCXXC。我们已经表达和表征这一领域的铜结合位点和构象的铜结合的后果。通过X射线吸收光谱（XAS）对该结构域的详细分析揭示，每个结合位点使用具有扭曲线性几何形状的两个半胱氨酸侧链以+1氧化态连接铜。铜诱导的氨基末端结构域的构象变化的分析表明，二级和三级结构的变化发生在铜结合。这些铜诱导的构象变化可能在体内ATP酶的功能和调节中起重要作用。除了提供重要的见解铜结合的蛋白质，这些结果表明铜贩运威尔逊病ATP酶的可能机制。
The Wilson disease copper-transporting ATPase plays a critical role in the intracellular trafficking of copper. Mutations in this protein lead to the accumulation of a toxic level of copper in the liver, kidney, and brain followed by extensive tissue damage and death. The ATPase has a novel aminoterminal domain (similar to 70 kDa) which contains six repeals of the copper binding motif GMTCXXC. We have expressed and characterized this domain with respect to the copper binding sites and the conformational consequences of copper binding. A detailed analysis of this domain by X-ray absorption spectroscopy (XAS) has revealed that each binding site ligates copper in the +1 oxidation state using two cysteine side chains with distorted linear geometry. Analysis of copper-induced conformational changes in the aminoterminal domain indicates that both secondary and tertiary structure changes take place upon copper binding. These copper-induced conformational changes could play an important role in the function and regulation of the ATPase in vivo. In addition to providing important insights on copper binding to the protein, these results suggest a possible mechanism of copper trafficking by the Wilson disease ATPase.