Observation of hydrogen-deuterium exchange of ubiquitin by direct analysis of electrospray capillary-skimmer dissociation with Fourier transform ion cyclotron resonance mass spectrometry.
Observation of hydrogen-deuterium exchange of ubiquitin by direct analysis of electrospray capillary-skimmer dissociation with Fourier transform ion cyclotron resonance mass spectrometry.
复制标题
通过傅里叶变换离子回旋共振质谱法直接分析电喷雾毛细管-撇渣器解离来观察泛素的氢-氘交换。
作者：
S. Akashi;Y. Naito;K. Takio
泛素是一种小细胞质蛋白，具有延伸的 β 片层和围绕疏水核心的 α 螺旋，其结构已通过氢-氘 (H/D) 交换标记并通过毛细管分离器解离和电喷雾电离-傅里叶变换离子回旋共振质谱 (ESI-FTICR MS) 进行连续分析来表征。在不同时间研究了每个碎片离子的氘含量，结果表明，氘掺入泛素骨架酰胺的速率根据酰胺氢的环境而变化。 N-末端β-链的酰胺氢显示出相当缓慢的交换，而35-39环的酰胺氢在暴露于氧化氘的短时间内就发生了交换。还可以评估氢键稳定性的差异。目前的数据与X射线和NMR分析获得的结构特征一致。尽管一些标记信息可能会因毛细管撇渣器解离过程中酰胺质子的扰乱而丢失，但结果表明本方法为蛋白质提供了有用的高阶结构信息。
The structure of ubiquitin, a small cytoplasmic protein with an extended beta-sheet and an alpha-helix surrounding a hydrophobic core, has been characterized by hydrogen-deuterium (H/D) exchange labeling in conjunction with successive analysis by capillary-skimmer dissociation with electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS). The deuterium content of each fragment ion was investigated at different times, and the results indicate that the deuterium incorporation rate into the backbone amides of ubiquitin varied depending on the environment of the amide hydrogens. Amide hydrogens of the N-terminal beta-strand showed quite slow exchange while those of the 35-39 loop were exchanged within a short exposure time to deuterium oxide. It was also possible to evaluate the difference in hydrogen-bond stability. The present data are consistent with the structural features obtained by X-Ray and NMR analyses. Although some of the labeling information might be lost by the scrambling of amide protons during capillary-skimmer dissociation, the results demonstrate that the present method provides useful higher-order structural information for proteins.