Evidence of H/D Exchange within Metal-Adducted Carbohydrates after Ion/Ion-Dissociation Reactions
Evidence of H/D Exchange within Metal-Adducted Carbohydrates after Ion/Ion-Dissociation Reactions
复制标题
DOI：
10.1021/jacs.3c05793
复制
发表时间：
2023-10-24
影响因子：
15
通讯作者：
Gallagher，Elyssia S.
中科院分区：
文献类型：
--
作者：
Gass，Darren T.;Cordes，Michael S.;Gallagher，Elyssia S.
碎片串联质谱（MS/MS）已成为获取生物分子序列和结构信息的最有效方法之一。离子/离子反应是竞争性反应，其中质子转移（PT）或电子转移（ET）可以在多电荷阳离子和单电荷阴离子之间的相互作用中发生。利用与荧光蒽的离子/离子反应为生物分子的结构解析提供了一种独特的片段形成方法。荧光蒽被认为是一种理想的阴离子试剂，因为它选择性地引起电子转移解离（ETD），并在与肽相互作用时最小化PT。然而，有限的研究试图了解荧光蒽──主要的、市售的阴离子试剂──如何与其他生物分子相互作用。在这里，我们应用氘标记来研究荧光蒽和二价金属加合碳水化合物（Ca2+, Mg2+， Co2+和Ni2+）之间的离子/离子反应机制。碳水化合物的氘标记使我们能够观察到离子/离子解离反应后发生氢/氘交换（HDX）的证据。氘损失的程度取决于几个因素，包括金属离子的物理性质和碎片结构。基于氘标记数据，我们提出了ETD、PTD和分子间PT─也称为HDX─机制。本研究提供了离子/离子和离子/分子反应机理的基本视角，并阐明了影响碳水化合物离子/离子和离子/分子反应的性质。总之，这可以提高区分复杂和异质生物分子的能力，比如碳水化合物。
Tandem mass spectrometry (MS/MS) using fragmentation has become one of the most effective methods for gaining sequence and structural information on biomolecules. Ion/ion reactions are competitive reactions, where either proton transfer (PT) or electron transfer (ET) can occur from interactions between multiply charged cations and singly charged anions. Utilizing ion/ion reactions with fluoranthene has offered a unique method of fragment formation for the structural elucidation of biomolecules. Fluoranthene is considered an ideal anion reagent because it selectively causes electron-transfer dissociation (ETD) and minimizes PT when interacting with peptides. However, limited investigations have sought to understand how fluoranthene─the primary, commercially available anion reagent─interacts with other biomolecules. Here, we apply deuterium labeling to investigate ion/ion reaction mechanisms between fluoranthene and divalent, metal-adducted carbohydrates (Ca2+, Mg2+, Co2+, and Ni2+). Deuterium labeling of carbohydrates allowed us to observe evidence of hydrogen/deuterium exchange (HDX) occurring after ion/ion dissociation reactions. The extent of deuterium loss is dependent on several factors, including the physical properties of the metal ion and the fragment structure. Based on the deuterium labeling data, we have proposed ETD, PTD, and intermolecular PT─also described as HDX─mechanisms. This research provides a fundamental perspective of ion/ion and ion/molecule reaction mechanisms and illustrates properties that impact ion/ion and ion/molecule reactions for carbohydrates. Together, this could improve the capability to distinguish complex and heterogeneous biomolecules, such as carbohydrates.