Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling.
Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling.
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DOI：
10.1007/s13361-015-1304-x
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发表时间：
2016-03
影响因子：
3.2
通讯作者：
Valentine SJ
中科院分区：
文献类型：
--
作者：
Khakinejad M;Kondalaji SG;Donohoe GC;Valentine SJ
结合气相氢氘交换（HDX）-质谱（MS）和分子动力学模拟（MDS）的离子迁移谱（IMS）已被用于通过电喷雾含有具有序列KKDDDDDIIKIIK的合成肽的样品产生的阴离子的结构研究。在这些实验中，已经评估了用于定位离子上的电荷位点以及用于利用碰撞诱导解离（CID）来揭示特定氨基酸残基内的氘摄取程度的分析方法的潜力。对于漫射（即，更长的）[M-2 H]2−离子，氘含量沿着降低，MDS数据表明D4和D 6残基是电荷位点，而对于更扩散的[M-3 H]3−离子，数据表明D4、D 7和C末端被去质子化。对迁移率选择的扩散[M-2 H]2−离子进行碎片化以确定单个氨基酸残基的氘摄取，揭示了掺入位点的氘保留程度。虽然扩散的[M-3 H]3−离子可能显示出更多的HD扰乱，但不可能根据氢可及性模型将HD扰乱与预期的氘吸收明确区分开来。IMS-HDX-MS/MS方法提供有关离子结构的相关细节的能力进行了讨论。此外，扩展的方法定位质子化位点上带正电荷的离子的能力。
Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M-2H]2− ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites whereas for the more diffuse [M-3H]3− ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M-2H]2− ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M-3H]3− ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.