Enhanced detection of phosphopeptides in matrix-assisted laser desorption/ionization mass spectrometry using ammonium salts
Enhanced detection of phosphopeptides in matrix-assisted laser desorption/ionization mass spectrometry using ammonium salts
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DOI：
10.1016/s1044-0305(98)00129-9
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发表时间：
1999-01-01
影响因子：
3.2
通讯作者：
Allison, J
中科院分区：
文献类型：
--
作者：
Asara, JM;Allison, J
基质辅助激光解吸电离质谱（MALDI MS）已成功地用于检测蛋白质中的磷酸化位点。应用可能受到限制的低响应的磷酸肽相比，非磷酸化的肽在MALDI MS。铵盐的基质/分析物溶液中的加入大大增强了磷酸肽的信号。在等摩尔混合物所示的实施例中，磷酸化肽峰在铵离子添加后变成光谱中的最大峰。这可以允许在未分级的蛋白水解消化混合物中鉴定磷酸肽。可以产生足够数量的质子化磷酸肽，使得它们可以进行源后衰变分析，以确认存在的磷酸基团的数量。该方法与常见的MALDI基质如α-氰基-4-羟基肉桂酸和2，5-二羟基苯甲酸以及铵盐如柠檬酸二铵和乙酸铵配合使用效果良好。（J Am Soc Mass Spectrom 1999，10，35-44）（C）1999美国质谱学会。
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used successfully to detect phosphorylation sites in proteins. Applications may be Limited by the low response of phosphopeptides compared to nonphosphorylated peptides in MALDI MS. The addition of ammonium salts to the matrix/analyte solution substantially enhances the signal for phosphopeptides. In examples shown for equimolar mixtures, the phosphorylated peptide peaks become the largest peaks in the spectrum upon ammonium ion addition. This can allow for the identification of phosphopeptides in an unfractionated proteolytic digestion mixture. Sufficient numbers of protonated phosphopeptides can be generated such that they can be subjected to postsource decay analysis, in order to confirm the number of phosphate groups present. The approach works well with the common MALDI matrices such as alpha-cyano-4-hydroxycinnamic acid and 2,5-dihydroxybenzoic acid, and with ammonium salts such as diammonium citrate and ammonium acetate. (J Am Soc Mass Spectrom 1999, 10, 35-44) (C) 1999 American Society for Mass Spectrometry.