A method to determine the ionization efficiency change of peptides caused by phosphorylation
A method to determine the ionization efficiency change of peptides caused by phosphorylation
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DOI：
10.1016/j.jasms.2007.08.010
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发表时间：
2007-11-01
影响因子：
3.2
通讯作者：
Wang, Yinsheng
中科院分区：
文献类型：
--
作者：
Gao, Yuan;Wang, Yinsheng
通过质谱法对蛋白质翻译后修饰进行定量评估通常需要考虑修饰引起的肽电离效率的变化。在此，我们介绍了一种使用专门设计的未标记肽来测量肽的相对电离效率的方法。在我们的设计中，所研究的肽，无论是未修饰的还是修饰的形式，都通过酶裂解位点与内标肽连接；因此，酶消化后，我们可以轻松获得所研究的肽与内标肽之间的 1:1 比例。然后可以根据修饰引起的目标肽离子与内标肽离子相对丰度比率的变化来计算修饰和未修饰肽的相对电离效率。我们通过评估磷酸化引入的四种肽的电离效率的变化来证明该方法的有用性。
Quantitative assessment of post-translational modifications in proteins by mass spectrometry often requires the consideration of the alteration in ionization efficiency of peptides induced by the modification. Herein, we introduced a method to measure the relative ionization efficiencies of peptides using specifically designed unlabeled peptides. In our design, the peptide under study, in either the unmodified or modified form, is linked with an internal standard peptide via an enzyme cleavage site; thus, after enzymatic digestion, we could obtain readily a 1:1 ratio between the peptide under investigation and the internal standard peptide. The relative ionization efficiencies of the modified and unmodified peptides can then be calculated from the modification-induced change in the ratio of relative abundances of the ion of the peptide of interest over that of the internal standard peptide. We demonstrated the usefulness of the method by assessing the change in ionization efficiencies of four peptides introduced by phosphorylation.