Department of Chemistry, Purdue University, West Lafayette, IN, 47907-2084, USA.
J Am Soc Mass Spectrom. 2017 Jun;28(6):991-1004. doi: 10.1007/s13361-016-1554-2. Epub 2017 Jan 3.
Here, we provide an overview of pathways available upon the gas-phase oxidation of peptides and DNA via ion/ion reactions and explore potential applications of these chemistries. The oxidation of thioethers (i.e., methionine residues and S-alkyl cysteine residues), disulfide bonds, S-nitrosylated cysteine residues, and DNA to the [M+H+O] derivative via ion/ion reactions with periodate and peroxymono-sulfate anions is demonstrated. The oxidation of neutral basic sites to various oxidized structures, including the [M+H+O], [M-H], and [M-H-NH] species, via ion/ion reactions is illustrated and the oxidation characteristics of two different oxidizing reagents, periodate and persulfate anions, are compared. Lastly, the highly efficient generation of molecular radical cations via ion/ion reactions with sulfate radical anion is summarized. Activation of the newly generated molecular radical peptide cations results in losses of various neutral side chains, several of which generate dehydroalanine residues that can be used to localize the amino acid from which the dehydroalanine was generated. The chemistries presented herein result in a diverse range of structures that can be used for a variety of applications, including the identification and localization of S-alkyl cysteine residues, the oxidative cleavage of disulfide bonds, and the generation of molecular radical cations from even-electron doubly protonated peptides. Graphical Abstract ᅟ.
在这里，我们提供了通过离子/离子反应对气相肽和 DNA 进行氧化的途径概述，并探讨了这些化学物质的潜在应用。展示了通过碘酸盐和过单硫酸盐阴离子与硫醚（即蛋氨酸残基和 S-烷基半胱氨酸残基）、二硫键、S-亚硝酰化半胱氨酸残基和 DNA 进行离子/离子反应将其氧化为 [M+H+O] 衍生物。通过离子/离子反应将中性碱性位点氧化为各种氧化结构，包括 [M+H+O]、[M-H] 和 [M-H-NH] 物种，并比较了两种不同氧化试剂（碘酸盐和过硫酸盐阴离子）的氧化特性。最后，总结了通过与硫酸根自由基阴离子的离子/离子反应高效生成分子自由基阳离子。新生成的分子自由基肽阳离子的激活导致各种中性侧链的损失，其中一些会产生脱氢丙氨酸残基，可用于定位产生脱氢丙氨酸的氨基酸。本文介绍的化学物质产生了广泛的结构，可用于各种应用，包括 S-烷基半胱氨酸残基的鉴定和定位、二硫键的氧化断裂以及甚至电子双质子化肽的分子自由基阳离子的生成。
