Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, Stockholm, Sweden.
Proteomics. 2011 Mar;11(6):1086-93. doi: 10.1002/pmic.201000432. Epub 2011 Feb 7.
The peptide identification process in shotgun proteomics is most frequently solved with search engines. Such search engines assign scores that reflect similarity between the measured fragmentation spectrum and the theoretical spectra of the peptides of a given database. However, the scores from most search engines do not have a direct statistical interpretation. To understand and make use of the significance of peptide identifications, one must thus be familiar with some statistical concepts. Here, we discuss different statistical scores used to show the confidence of an identification and a set of methods to estimate these scores. We also describe the variance of statistical scores and imperfections of scoring functions of peptide-spectrum matches.
在鸟枪法蛋白质组学中，肽鉴定过程最常通过搜索引擎来解决。这些搜索引擎会分配分数，反映测量的碎片谱与给定数据库中肽的理论谱之间的相似性。然而，大多数搜索引擎的分数没有直接的统计解释。因此，要理解和利用肽鉴定的显著性，就必须熟悉一些统计概念。在这里，我们讨论了用于显示鉴定置信度的不同统计分数以及估计这些分数的方法。我们还描述了统计分数的方差和肽-谱匹配评分函数的不完美性。
