Desalting protein ions in native mass spectrometry using supercharging reagents.
Desalting protein ions in native mass spectrometry using supercharging reagents.
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DOI：
10.1039/c4an01085j
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发表时间：
2014-10-07
期刊：
影响因子：
--
通讯作者：
Williams ER
中科院分区：
文献类型：
--
作者：
Cassou CA;Williams ER
研究了增压试剂 m-NBA 和环丁砜对钠离子加成到使用天然质谱形成的蛋白质离子的影响。通过电喷雾电离含有毫摩尔浓度 NaCl 的水溶液形成的蛋白质离子上存在广泛的钠加合，这可以通过将给定电荷状态的信号分布在多个加合离子上来降低灵敏度，并且可以降低无法解析单个加合物的大蛋白质和非共价复合物的质量测量精度。与不使用增压剂相比，当向含钠水溶液中添加 1.5% m-NBA 或 2.5% 环丁砜时，与可解析加合物的 10 个小蛋白 (8.6–29 kDa) 形成的最丰富离子加合的钠离子平均数量分别平均减少 58% 或 80%。环丁砜在减少钠离子加合和保持非共价蛋白质-配体和蛋白质-蛋白质相互作用方面比 m-NBA 更有效。用 2.5% 环丁砜脱盐能够检测与 146 kDa 同四聚体 LDH 结合的 79.7 kDa 全转铁蛋白和 NADH 的几种糖基化形式，否则由于广泛的钠加合导致峰展宽，这些形式无法解决。尽管环丁砜在蛋白质离子脱盐方面比 m-NBA 更有效，但 m-NBA 可以减少高 m/z 下的盐簇，并可以通过减少化学噪音来提高蛋白质离子的信噪比。脱盐可能是这些增压试剂与溶液中的钠离子结合的结果，从而减少了可与蛋白质离子加合物的钠。
Effects of the supercharging reagents m-NBA and sulfolane on sodium ion adduction to protein ions formed using native mass spectrometry were investigated. There is extensive sodium adduction on protein ions formed by electrospray ionization from aqueous solutions containing millimolar concentrations of NaCl, which can lower sensitivity by distributing the signal of a given charge state over multiple adducted ions and can reduce mass measuring accuracy for large proteins and non-covalent complexes for which individual adducts cannot be resolved. The average number of sodium ions adducted to the most abundant ion formed from ten small (8.6–29 kDa) proteins for which adducts can be resolved is reduced by 58% or 80% on average, respectively, when 1.5% m-NBA or 2.5% sulfolane are added to aqueous solutions containing sodium compared to without the supercharging reagent. Sulfolane is more effective than m-NBA at reducing sodium ion adduction and at preserving non-covalent protein-ligand and protein-protein interactions. Desalting with 2.5% sulfolane enables detection of several glycosylated forms of 79.7 kDa holo-transferrin and NADH bound to the 146 kDa homotetramer LDH, which are otherwise unresolved due to peak broadening from extensive sodium adduction. Although sulfolane is more effective than m-NBA at protein ion desalting, m-NBA reduces salt clusters at high m/z and can increase the signal-to-noise ratios of protein ions by reducing chemical noise. Desalting is likely a result of these supercharging reagents binding sodium ions in solution, thereby reducing the sodium available to adduct to protein ions.
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影响因子：
7.4
作者：
Flick, Tawnya G.;Cassou, Catherine A.;Chang, Terrence M.;Williams, Evan R.
通讯作者：
Williams, Evan R.
影响因子：
14.8
作者：
Hernandez, Helena;Robinson, Carol V.
通讯作者：
Robinson, Carol V.
影响因子：
2.9
作者：
Jiang, Y;Hofstadler, SA
通讯作者：
Hofstadler, SA
影响因子：
2.9
作者：
FU, DT;VANHALBEEK, H
通讯作者：
VANHALBEEK, H
影响因子：
2
作者：
Benkestock, K;Edlund, PO;Roeraade, J
通讯作者：
Roeraade, J