Computational Principles of Determining and Improving Mass Precision and Accuracy for Proteome Measurements in an Orbitrap
Computational Principles of Determining and Improving Mass Precision and Accuracy for Proteome Measurements in an Orbitrap
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DOI：
10.1016/j.jasms.2009.05.007
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发表时间：
2009-08-01
影响因子：
3.2
通讯作者：
Mann, Matthias
中科院分区：
文献类型：
--
作者：
Cox, Juergen;Mann, Matthias
精确蛋白质组学需要高分辨率和高质量精度的肽测量。Orbitrap仪器在色谱时间尺度上具有优异的分辨率，其设计有利于实现非常高的质量精度。在这里，我们描述了如何通过考虑所有相关的测量，从质谱峰开始，到其色谱洗脱剖面、同位素包膜和SILAC测量中的稳定同位素对，依次提高每个肽的质量精度。我们提取肽电荷对，通过样条插值对Orbitrap质量尺度进行非线性再校准。由电荷对确定的质量值的偏差用于将质量精度转换为后续数据库搜索的质量精度。修正后的质量精度与数据库识别独立确定的质量精度一致。个体质量偏差范围从具有许多相关质量测量和良好信号强度的肽的100 ppb以下到具有很少质量测量和信号接近噪声水平的肽的低ppm。这种极高的个性化质量精度相当于数据库识别分数的大幅提高。（J Am Soc质谱鳟鱼2009,20,1477-1485）(C) 2009由Elsevier Inc.代表美国质谱学会出版
Precision proteomics requires high-resolution and high mass accuracy peptide measurements. The Orbitrap instrument achieves excellent resolution on a chromatographic time scale and its design is favorable for very high mass accuracy. Here we describe how mass precision for each peptide increases successively by considering all associated measurements, starting from the MS peak and proceeding to its chromatographic elution profile, isotope envelope, and stable isotope pair in SILAC measurements. We extract peptide charge pairs to perform nonlinear recalibration of the Orbitrap mass scale through spline interpolation. The deviation of mass values determined from charge pairs is used to convert mass precision to mass accuracy for subsequent database search. The corrected mass precision is consistent with the mass accuracy independently determined by database identification. Individual mass deviations range from below 100 ppb for peptides with many associated mass measurements and good signal intensities to low ppm for peptides with few mass measurements and signals close to the noise level. This extremely high and individualized mass accuracy is equivalent to a Substantial increase in database identification score. (J Am Soc Mass Spec trout 2009, 20, 1477-1485) (C) 2009 Published by Elsevier Inc. on behalf of American Society for Mass Spectrometry