Using statistical models to identify factors that have a role in defining the abundance of ions produced by tandem MS
Using statistical models to identify factors that have a role in defining the abundance of ions produced by tandem MS
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DOI：
10.1021/ac0700272
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发表时间：
2007-08-01
影响因子：
7.4
通讯作者：
Whittaker, John C.
中科院分区：
文献类型：
--
作者：
Barton, Sheila J.;Richardson, Sylvia;Whittaker, John C.
用四极飞行时间质谱仪获得了5448个多肽串联质谱库，用于从胰酶消化的蛋白质中提取多肽。用Mascot算法从它们的质谱图中鉴定多肽。然后使用统计模型来研究影响离子形成丰度的因素。由于人们认为不同的因素可能会影响每种离子的形成，因此分别为b离子和y离子建立了模型。有几个因素被发现对形成的离子的丰度有非常显著的影响。这些包括碎裂后形成的离子的实际质量以及解理的位置。碎裂肽的组成也是重要的，碎裂点两侧的氨基酸影响产生的离子的丰度。为了增加对碎裂机理的了解，还在一个单独的模型中研究了这些残留物的几个物理化学性质的影响。总而言之，为b和y离子建立的模型提供了对形成的离子丰度的有用表征，并且这些信息可以用于开发改进的多肽识别算法。
A database of 5448 peptide tandem mass spectra acquired in a quadrupole time-of-flight mass spectrometer was generated for peptides derived from proteins digested with trypsin. Peptides were identified from their mass spectra by the Mascot algorithm. Statistical models were then used to investigate factors influencing the abundance of ions formed. Separate models were formulated for b and y ions as it was thought that different factors may influence the formation of each type of ion. Several factors were found to have a highly significant influence on the abundance of ions formed. These include the actual mass of the ion formed after fragmentation as well as the location of the cleavage. The composition of the fragmenting peptide was also found to be important, and amino acids either side of the fragmentation site influenced the abundance of ions produced. To increase understanding of fragmentation mechanisms, the effect of several physicochemical properties of these residues was also investigated in a separate model. In conclusion, the models formulated for b and y ions provide useful characterization of the abundance of ions formed, and this information could be used to develop improved algorithms for peptide identification.