Peptide sequencing and characterization of post-translational modifications by enhanced ion-charging and liquid chromatography electron-transfer dissociation tandem mass spectrometry
Peptide sequencing and characterization of post-translational modifications by enhanced ion-charging and liquid chromatography electron-transfer dissociation tandem mass spectrometry
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DOI：
10.1021/ac701700g
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发表时间：
2007-12-15
影响因子：
7.4
通讯作者：
Jensen, Ole N.
中科院分区：
文献类型：
--
作者：
Kjeldsen, Frank;Giessing, Anders M. B.;Jensen, Ole N.
我们测试了间硝基苄基醇（mNBA）作为一种提高色氨酸多肽和磷酸多肽ESI生成的质子化气相分子离子平均电荷态的方法。将不同浓度的m-NBA加入到与ESI串联质谱联用的液相色谱系统的流动相中。nba只增加了0.1%的变化。所鉴定的色氨酸BSA肽的平均电荷态为2.2+ ~ 2.6+。结果，BSA肽的主要电荷态由2+变为>= 3+。为了评估多肽电荷增强的益处，比较了2+和3+电荷状态下的BSA肽的ETD片段效率和Mascot肽评分。在所有情况下，除了一个，三电荷肽比类似的2+肽离子更有效地碎片化。平均而言，三次充电肽的Mascot分数（24个单位）比双重充电肽高68%。m-NBA还将磷酸肽的平均电荷状态提高了0.5个电荷单位。在LC溶剂中加入m-NBA对色氨酸肽进行电荷增强的操作简便和分析优势表明，该试剂在采用ETD-MS/MS和相关技术的蛋白质组学研究中具有普遍的应用价值。
We have tested the effect of m-nitrobenzyl alcohol (mNBA) as a method to increase the average charge state of protonated gas-phase molecular ions generated by ESI from tryptic peptides and phosphopeptides. Various concentrations of m-NBA were added to the mobile phases of a liquid chromatography system coupled to an ESI tandem mass spectrometer. Addition of just 0.1% m-NBA changed. the average charge state for the identified tryptic BSA peptides from 2.2+ to 2.6+. As a result, the predominant charge states for BSA peptides were changed from 2+ to >= 3+. To evaluate the benefits of peptide charge enhancement, the ETD fragmentation efficiency and Mascot peptide score were compared for BSA peptides in charge states 2+ and 3+. In all cases but one, triply charged peptides fragmented more efficiently than the analogues 2+ peptide ions. On average, triply charged peptides received a 68% higher Mascot score (24 units) than doubly charged peptides. m-NBA also increased the average charge state of phosphopeptides by up to 0.5 charge unit The ease of implementation and the analytical benefits of charge enhancement of tryptic peptides by addition of m-NBA to the LC solvents suggest the general application of this reagent in proteomic studies that employ ETD-MS/MS and related techniques.