Shifts in peptide and protein charge state distributions with varying spray tip orifice diameter in nanoelectrospray Fourier transform ion cycitron resonance mass spectrometry
Shifts in peptide and protein charge state distributions with varying spray tip orifice diameter in nanoelectrospray Fourier transform ion cycitron resonance mass spectrometry
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DOI：
10.1021/ac0301402
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发表时间：
2003-11-01
影响因子：
7.4
通讯作者：
Cole, RB
中科院分区：
文献类型：
--
作者：
Li, Y;Cole, RB
使用血管紧张素I（M-r = 1296）、胰岛素（M-r = 5774）和泛素（M-r = 8560）作为测试分析物，研究了用于纳米电喷雾质谱（nano-ES-MS）的喷嘴直径对质谱电荷态分布的影响。在各种实验条件下，测试肽和蛋白质的电荷状态分布一致地随着尖端孔口直径减小而向较高值偏移。该发现表明，使用窄直径毛细管可以促进更高电荷态离子的形成，这些离子是串联质谱实验中更具反应性的前体。不同直径的纳米喷雾毛细管获得的电荷状态分布进行了详细的比较，同时系统地改变实验参数，如样品流速，分析物浓度，溶剂组合物，和电喷雾电流。从窄直径毛细管获得更高电荷状态的一般趋势始终保持不变，但具有较小孔口的尖端对样品流速更敏感（平均电荷状态随着流量的升高而显著降低），而具有较大孔口的尖端对分析物浓度和溶液pH值更敏感（随着每一个降低，平均电荷状态增加）。
The influence of the diameter of the spray tip employed for nano-electrospray mass spectrometry (nano-ES-MS) upon mass spectral charge state distributions was investigated using angiotensin I (M-r = 1296), insulin (M-r = 5774), and ubiquitin (M-r = 8560) as test analytes. Under a variety of experimental conditions, the charge state distributions of the test peptides and protein consistently shifted toward higher values as the tip orifice diameter decreased. Ibis finding indicates that the use of narrow diameter capillaries can promote the formation of higher charge state ions that are more reactive precursors in tandem mass spectrometry experiments. A detailed comparison of charge state distributions obtained for nanospray capillaries of varying diameters was undertaken while systematically varying experimental parameters such as sample flow rate, analyte concentration, solvent composition, and electrospray current. The general tendency to obtain higher charge states from narrow diameter capillaries was conserved throughout, but tips with smaller orifices were more sensitive to sample flow rate (the average charge state was lowered significantly as flow was raised), whereas tips with bigger,orifices were more sensitive to analyte concentration and pH of the solution (as each was lowered, the average charge state increased).