Characterization of the Oxazolone and Macrocyclic Motifs in the b n ( n = 2–5) Product Ions from Collision-Induced Dissociation of Protonated Oligoglycine Peptides with Isomer-Selective, Cryogenic Vibrational Spectroscopy
Characterization of the Oxazolone and Macrocyclic Motifs in the b n ( n = 2–5) Product Ions from Collision-Induced Dissociation of Protonated Oligoglycine Peptides with Isomer-Selective, Cryogenic Vibrational Spectroscopy
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使用异构体选择性低温振动光谱法表征质子化寡甘氨酸肽碰撞诱导解离的 b n ( n = 2â5) 产物离子中的恶唑酮和大环基序
DOI：
10.1021/jasms.3c00372
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发表时间：
2024
影响因子：
3.2
通讯作者：
McCoy, Anne B.
中科院分区：
文献类型：
--
作者：
Mohamed, Ahmed;Rana, Abhijit;Perez, Evan;Dahlmann, Franziska;Fry, Allison;Menges, Fabian S.;van Stipdonk, Michael;Jäger, Svenja;Boyer, Mark A.;McCoy, Anne B.
小的质子化肽的碰撞诱导解离（CID）导致b型碎片离子的形成，所述b型碎片离子可以与由不同的共价分子内键合排列驱动的几个结构基序一起发生。在这里，我们描述了所谓的“恶唑酮”和“大环”bnion结构，发生在CID的寡甘氨酸肽（Gn）离子（n= 2-6）。这是通过获取的低温冷却，D2-taggedbnions获得使用异构体选择性，双色IR-IR光漂白和分析它们与预测（DFT）的谐波光谱的候选结构的振动带模式。b4生成恶唑酮和大环异构体，而b2和b3只生成恶唑酮，b5生成大环。因此，n= 4对应于同时存在Oxa和MC形式的最小尺寸。
Collision-induced dissociation (CID) of small, protonated peptides leads to the formation of b-type fragment ions that can occur with several structural motifs driven by different covalent intramolecular bonding arrangements. Here, we characterize the so-called “oxazolone” and “macrocycle”bnion structures that occur upon CID of oligoglycine peptides (Gn) ions (n= 2–6). This is determined by acquiring the vibrational band patterns of the cryogenically cooled, D2-taggedbnions obtained using isomer-selective, two-color IR–IR photobleaching and analyzing them with predicted (DFT) harmonic spectra for the candidate structures. Both oxazolone and macrocyclic isomers are formed byb4, whereas only oxazolone species are created forb2andb3and the macrocycle is created forb5. As such,n= 4 corresponds to the minimum size where both Oxa and MC forms are present.