Gas-phase microsolvation of ubiquitin: investigation of crown ether complexation sites using ion mobility-mass spectrometry
Gas-phase microsolvation of ubiquitin: investigation of crown ether complexation sites using ion mobility-mass spectrometry
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DOI：
10.1039/c6an01377e
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发表时间：
2016-01-01
期刊：
影响因子：
4.2
通讯作者：
Pagel, Kevin
中科院分区：
文献类型：
--
作者：
Goeth, Melanie;Lermyte, Frederik;Pagel, Kevin
在这项研究中，泛素及其赖氨酸精氨酸突变体的气相结构进行了研究，使用离子迁移质谱（IM-MS）和电子转移解离质谱（ETD-MS）。冠醚分子连接到蛋白质的正电荷位点，并分析所得的非共价复合物。碰撞诱导解离（CID）的实验表明，野生型和突变冠醚复合物之间的相对能量差异。进行ETD-MS实验以鉴定冠醚结合位点。虽然不能揭示所有的结合位点，但数据证实第一冠醚能够与N-末端结合。IM-MS实验表明，当冠醚连接时，野生型泛素的特定电荷状态具有更紧凑的结构。然而，泛素突变体的数据显示，只有特定的赖氨酸残基有助于电荷微溶剂化的效果。仅观察到一个紧凑的研究突变体，其中赖氨酸没有接近的相互作用的合作伙伴。另一方面，当赖氨酸残基参与盐桥时，冠醚的连接对结构几乎没有影响。
In this study the gas-phase structure of ubiquitin and its lysine-to-arginine mutants was investigated using ion mobility-mass spectrometry (IM-MS) and electron transfer dissociation-mass spectrometry (ETD-MS). Crown ether molecules were attached to positive charge sites of the proteins and the resulting non-covalent complexes were analysed. Collision induced dissociation (CID) experiments revealed relative energy differences between the wild type and the mutant crown-ether complexes. ETD-MS experiments were performed to identify the crown ether binding sites. Although not all of the binding sites could be revealed, the data confirm that the first crown ether is able to bind to the N-terminus. IM-MS experiments show a more compact structure for specific charge states of wild type ubiquitin when crown ethers are attached. However, data on ubiquitin mutants reveal that only specific lysine residues contribute to the effect of charge microsolvation. A compaction is only observed for one of the investigated mutants, in which the lysine has no proximate interaction partner. On the other hand when the lysine residues are involved in salt bridges, attachment of crown ethers has little effect on the structure.