Fragmentation of phosphorylated peptide ions via interaction with electronically excited metastable argon atoms was studied in a linear trap - time-of-flight mass spectrometer. Doubly charged ions of phosphorylated peptides from an Enolase digest were produced by electrospray ionization and subjected to a metastable atom beam in the linear trap. The metastable argon atoms were generated using a glow-discharge source. An intensive series of c- and z- ions were observed in all cases, with the phosphorylation group intact. The formation of molecular radical cations with reduced charge indicated that an electron transfer from a highly excited metastable state of argon to the peptide cation occurred. Additionally, singly charged Bradykinin, Substance P and Fibrinopeptide A molecular ions were fragmented via interaction with electronically excited metastable helium atoms. The fragmentation mechanism was different in this case and involved Penning ionization.

中文翻译：

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通过与亚稳态原子的相互作用使磷酸化和单电荷肽离子碎裂

在线性阱-飞行时间质谱仪中研究了磷酸化肽离子通过与电子激发的亚稳态氩原子相互作用而发生的碎裂。来自烯醇酶消化的磷酸化肽的双电荷离子通过电喷雾电离产生，并在线性阱中受到亚稳态原子束的影响。亚稳态氩原子是使用辉光放电源产生的。在所有情况下都观察到一系列密集的 c- 和 z- 离子，磷酸化基团完好无损。电荷减少的分子自由基阳离子的形成表明，发生了从氩的高度激发亚稳态到肽阳离子的电子转移。此外，单电荷缓激肽，物质 P 和纤维蛋白肽 A 分子离子通过与电子激发的亚稳态氦原子相互作用而破碎。在这种情况下，碎裂机制不同，涉及 Penning 电离。