DETERMINATION OF MONOISOTOPIC MASSES AND ION POPULATIONS FOR LARGE BIOMOLECULES FROM RESOLVED ISOTOPIC DISTRIBUTIONS
DETERMINATION OF MONOISOTOPIC MASSES AND ION POPULATIONS FOR LARGE BIOMOLECULES FROM RESOLVED ISOTOPIC DISTRIBUTIONS
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DOI：
10.1016/1044-0305(95)00017-8
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发表时间：
1995-04-01
影响因子：
3.2
通讯作者：
MCLAFFERTY, FW
中科院分区：
文献类型：
--
作者：
SENKO, MW;BEU, SC;MCLAFFERTY, FW
电喷雾离子化与傅里叶变换质谱法的结合可以分析大生物分子，质量测量误差小于1 ppm。大量的原子纳入这些分子的结果在一个低的概率为所有单一同位素物种。这可能会错误分配特定峰中的重同位素数量，并产生+/-1 Da的质量误差，尽管超出小数位的测量确定性大于0.1 Da。使用统计检验将测量的同位素分布与相同平均分子质量的模型分子的分布进行比较，这允许分配单一同位素质量，即使在光谱中没有单一同位素峰的情况下也是如此。统计测试产生与分布中的分子数量成反比的误差水平，这允许估计捕获的离子单元中的离子数量。已经确定，通过这种方法，需要128个电荷来产生3：1的信噪比，这与以前的实验方法很好地相关。
The coupling of electrospray ionization with Fourier-transform mass spectrometry allows the analysis of large biomolecules with mass-measuring errors of less than 1 ppm. The large number of atoms incorporated in these molecules results in a low probability for the all-monoisotopic species. This produces the potential to misassign the number of heavy isotopes in a specific peak and make a mass error of +/-1 Da, although the certainty of the measurement beyond the decimal place is greater than 0.1 Da. Statistical tests are used to compare the measured isotopic distribution with the distribution for a model molecule of the same average molecular mass, which allows the assignment of the monoisotopic mass, even in cases where the monoisotopic peak is absent from the spectrum. The statistical test produces error levels that are inversely proportional to the number of molecules in a distribution, which allows an estimation of the number of ions in the trapped ion cell. It has been determined, via this method that 128 charges are required to produce a signal-to-noise ratio of 3:1, which correlates well with previous experimental methods.