Interpreting the Charge State Assignment in Electrospray Mass Spectra of Bioparticles
Interpreting the Charge State Assignment in Electrospray Mass Spectra of Bioparticles
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DOI：
10.1021/ac102676z
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发表时间：
2011-03-15
影响因子：
7.4
通讯作者：
Peng, Wen-Ping
中科院分区：
文献类型：
--
作者：
Tseng, Yao-Hsin;Uetrecht, Charlotte;Peng, Wen-Ping
在异质蛋白质复合物和其他生物颗粒的电喷雾电离质谱中，准确的质量测定常常因单个信号的电荷状态测定的不准确性而受到阻碍。在这里，我们描述了一种算法，可以自动最小化一系列具有不同电荷数的相关离子峰的标准偏差。该算法假设质量不变，并允许确定峰值系列中的正确电荷状态。当找到电荷状态系列的最小标准偏差时，分析结果会产生周期性模式，可以将其解释为谐振子。我们观察到，所获取的质谱中远小于 1000 的质量分辨率足以实现正确的电荷态分配。此外，可以通过检查分析模式中周期性的损失来识别混合物种的边界。我们在新颖的光谱和文献中报告的光谱上成功测试了我们的算法，样品质量高达数百万道尔顿，例如病毒颗粒、聚乙二醇聚合物和聚苯乙烯纳米颗粒。
In electrospray ionization mass spectra of heterogeneous protein complexes and other bioparticles, accurate mass determination is often hampered by the inaccuracy in determination of the charge states for individual signals. Here, we describe an algorithm that automatically minimizes the standard deviation in a series of related ion peaks with varying numbers of charges. The algorithm assumes that the mass is invariant and allows the determination of the correct charge state in a peak series. The analysis results in a periodic pattern, which can be interpreted as a harmonic oscillator, when the minimum standard deviation of a charge state series is found. We observed that a mass resolution of much less than 1000 in the acquired mass spectra is sufficient to achieve a correct charge state assignment. Moreover, the boundaries of mixed species can be identified by examining the loss of periodicity in the pattern of the analysis. We tested our algorithm successfully on novel spectra and on spectra reported in the literature with sample masses up to several million Dalton, e.g., viral particles, polyethylene glycol polymers, and polystyrene nanoparticles.