High-Pressure Electrospray Ionization Yields Supercharged Protein Complexes from Native Solutions While Preserving Noncovalent Interactions
High-Pressure Electrospray Ionization Yields Supercharged Protein Complexes from Native Solutions While Preserving Noncovalent Interactions
复制标题
高压电喷雾电离从天然溶液中产生增压蛋白质复合物，同时保留非共价相互作用
DOI：
10.1021/acs.analchem.0c01965
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发表时间：
2020
影响因子：
7.4
通讯作者：
Huilin Li
中科院分区：
文献类型：
--
作者：
Zhibin Yin;Jing Huang;Hui Miao;Ou Hu;Huilin Li
增加天然溶液中蛋白质复合物的电荷状态，同时保留天然质谱（MS）中的非共价相互作用，为更深入地了解气相蛋白质结构提供了很好的机会。先前的几项研究已经揭示了高压在增压小蛋白质中的可能性，而其在天然条件下增压大蛋白质组装体的能力以及它如何影响蛋白质结构仍然是悬而未决的问题。在这里，我们证明了高压诱导的增压策略提供了独特的优势，增压蛋白质复合物的最高电荷状态超过瑞利极限（ZR），同时保持天然的拓扑结构。通过研究32个蛋白质和蛋白质复合物的分子量（MW）范围从8.58到801 kDa，我们表明，增加的大分子离子的平均电荷状态有很强的依赖于天然蛋白质的构象和MW的表面积。讨论了可能影响高压诱导对大分子离子的增压能力的因素。此外，使用碰撞截面（CCS）的变化作为一个功能的电荷状态，我们调查的气体压力和电荷状态的蛋白质和蛋白质复合物的气相结构的影响。一旦增压，较小的蛋白质具有最大的CCS变化，而大分子蛋白质复合物受影响较小。结果表明，电荷和带电的表面碱性残基的表面密度有助于观察到的CCS电荷学科的所有大分子的调查。两者合计，这里提出的结果表明，增加气体压力的离子源提供了一个快速，简单，可控的增压方法，提供潜力，促进进一步应用的本地自上而下的MS分析，提高传输，碎片，和检测效率。
Increasing charge state of protein complexes from native solutions while preserving noncovalent interactions in native mass spectrometry (MS) offers great opportunity to gain deeper insights into gas-phase protein structures. Several previous studies have disclosed the possibility of high pressure in supercharging small proteins, whereas its capability to supercharge large protein assemblies under native conditions and how it might affect protein structures remain open questions. Herein, we demonstrated that the high-pressure-induced supercharging strategy affords unique advantages of supercharging protein complexes with the highest charge state surpassing the Rayleigh limit (ZR) and concurrently preserving native-like topology. By examining 32 proteins and protein complexes with molecular weights (MWs) ranging from 8.58 to 801 kDa, we demonstrated that the increased average charge states of macromolecular ions have a strong dependence on the surface areas of native protein conformations and MWs. Factors that might contribute to the high-pressure-induced supercharging capability toward macromolecular ions were discussed. Furthermore, using collision cross section (CCS) variation as a function of charge state, we investigate the effects of gas pressure and charge states on gas-phase structures of proteins and protein complexes. Smaller proteins have the largest CCS variations once supercharged, while macromolecular protein complexes are less affected. The results revealed that both surface density of charge and charged surface basic residues contribute to the observed CCS-charge disciplines for all the macromolecules investigated. Taken together, the results presented here indicate that increasing gas pressure in the ion source affords a rapid, simple, and controlled supercharging method, offering the potency of facilitating further applications of native top-down MS analysis with improved transmission, fragmentation, and detection efficiency.