Cold-Induced Changes in the Protein Ubiquitin
Cold-Induced Changes in the Protein Ubiquitin
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DOI：
10.1371/journal.pone.0037270
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发表时间：
2012-06-21
期刊：
影响因子：
3.7
通讯作者：
Zweckstetter, Markus
中科院分区：
文献类型：
--
作者：
Cho, Min-Kyu;Xiang, ShengQi;Zweckstetter, Markus
构象变化对于蛋白质-蛋白质和蛋白质-配体识别至关重要。在这里，我们使用核磁共振波谱法探讨了过冷水中低温下蛋白质泛素结构的变化。我们证明泛素可以很好地折叠到 263 K，尽管疏水核心发生了轻微的重排。然而，酰胺质子化学位移在过冷溶液中表现出非线性温度依赖性，并且主链氢键在最容易发生冷变性的区域中变得较弱。我们的数据表明，泛素β折叠中氢键的减弱可能是泛素冷变性过程中发生的第一个事件。有趣的是，同一区域与泛素-蛋白质复合物密切相关，表明泛素的这一部分更容易适应复合物形成所需的构象变化。
Conformational changes are essential for protein-protein and protein-ligand recognition. Here we probed changes in the structure of the protein ubiquitin at low temperatures in supercooled water using NMR spectroscopy. We demonstrate that ubiquitin is well folded down to 263 K, although slight rearrangements in the hydrophobic core occur. However, amide proton chemical shifts show non-linear temperature dependence in supercooled solution and backbone hydrogen bonds become weaker in the region that is most prone to cold-denaturation. Our data suggest that the weakening of the hydrogen bonds in the beta-sheet of ubiquitin might be one of the first events that occur during cold-denaturation of ubiquitin. Interestingly, the same region is strongly involved in ubiquitin-protein complexes suggesting that this part of ubiquitin more easily adjusts to conformational changes required for complex formation.