Isotope edited product ion assignment by α-N labeling of peptides with [2H3(50%)]2,4-dinitrofluorobenzene
Isotope edited product ion assignment by α-N labeling of peptides with [2H3(50%)]2,4-dinitrofluorobenzene
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DOI：
10.1016/s1044-0305(99)00013-6
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发表时间：
1999-05-01
影响因子：
3.2
通讯作者：
Chen, YH
中科院分区：
文献类型：
--
作者：
Chen, XH;Anderson, VE;Chen, YH
对Sanger‘s鉴定多肽N-末端的方法进行了同位素修饰，以辅助串联质谱仪进行多肽测序。用2，4-二硝基氟苯和[H-2(3)]-2，4-二硝基氟苯等摩尔混合物对Val-His-Leu-TKR-Pro-Val-Glu-Lys进行衍生化。在优化的衍生化条件下，cr-氨基可以被衍生化，而赖氨酸侧链上的E-胺和组氨酸的咪唑仍未被衍生化。用电喷雾电离串联质谱仪(ESI-MS/MS)和液相色谱(LC)-ESI-MS对α-二硝基苯改性多肽进行了表征。[M+H](+)离子呈双峰结构，m/z为3，[M+2H](2+)离子为双峰，m/z为1.5。采用了MS/MS方法，其中两个同位素[M+2H](2+)离子在第二个四极杆中交替受到碰撞诱导解离。电离源的碎裂产生了与在第二个四极杆碎裂过程中观察到的相同的产物离子图案。在产物离子质谱图中，N端的a离子和b离子(未观察到c离子)为双重态，m/z为3或1.5，而C端的y离子和z离子(未观察到x离子)为质量相同的单重态。因此，含有用二硝基苯基衍生的N-末端的产物离子与含有C-末端的产物离子明确地区分开来。二硝基苯改性一般增强了a和b离子的产生，而不减少y和z离子的产量。(C)1999年美国质谱学学会。(C)1999年美国质谱学学会。
An isotopic modification of Sanger's method for identifying peptide N-termini has been developed to assist peptide sequencing by tandem mass spectrometry. Tryptic peptides, such as Val-His-Leu-Tkr-Pro-Val-Glu-Lys, are derivatized with an equimolar mixture of 2,4-dinitrofluorobenzene and [H-2(3)]2,4-dinitrofluorobenzene. Under optimized derivatization conditions, the cr-amino group could be derivatized while the E-amine of the lysine side chain and the imidazole of histidine remained underivatized. The a-dinitrophenyl modified peptides were characterized by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) and liquid chromatography (LC)-ESI-MS. The [M + H](+) ions showed a doublet pattern with a Delta m/z of 3 and the [M + 2H](2+) ions were recognized as doublets with a Delta m/z of 1.5. MS/MS was employed where both isotopic [M + 2H](2+) ions were alternately subjected to collision-induced dissociation in the second quadrupole. Fragmentation in the ionization source generated identical product ion patterns that were observed during fragmentation in the second quadrupole. In the product ion mass spectra, the N-terminal a and b ions (no c ion observed) are doublets with a Delta m/z of 3 or 1.5, while the C-terminal y and z ions (no x ion observed) are singlets appearing at identical masses. Thus, the product ions containing the N-terminus derivatized with a dinitrophenyl group are unequivocally distinguished from the product ions containing the C-terminus. The dinitrophenyl modification generally enhanced the production of a and b ions without diminishing y and z ion yields. (C) 1999 American Society for Mass Spectrometry. (C) 1999 American Society for Mass Spectrometry.