Gas-phase structure and fragmentation pathways of singly protonated peptides with N-terminal arginine.
Gas-phase structure and fragmentation pathways of singly protonated peptides with N-terminal arginine.
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DOI：
10.1021/jp108452y
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发表时间：
2010-11-25
影响因子：
3.3
通讯作者：
Paizs, Bela
中科院分区：
文献类型：
--
作者：
Bythell, Benjamin J.;Csonka, Istvan P.;Suhai, Sandor;Barofsky, Douglas F.;Paizs, Bela
采用碰撞诱导解离（CID）、分子力学和密度泛函理论（DFT）计算方法，研究了单质子化肽段-它表明，尽管电离质子被强烈螯合在胍基团，质子化的RGD可以很容易地被片段化的电荷导向的碎片化途径。这是由于C-末端或天冬氨酸COOH质子的容易移动，从而产生盐桥（SB）稳定的结构。这些SB中间体可以直接断裂以产生b2离子或容易地重排以形成酸酐，从酸酐可以形成b2和b2+H2O片段。形成b2和b2+H2O所需的盐桥稳定和酸酐过渡结构（TS）的能量比其传统的电荷溶剂化对应物低得多。这些机制为SB和酸酐结构在质子化肽片段化中的作用提供了令人信服的证据，这补充并支持了我们最近对胰蛋白酶系统的发现（Bythell，B. J.道：Suhai，S.; Somogyi，A.;派兹，B。J. Am.化学会，2009，131，14057-14065）。除了这些发现，我们还报告的机制，形成的b1离子，中性损失（H2O，NH3，胍）碎片离子和d3离子。
The gas-phase structures and fragmentation pathways of the singly protonated peptide arginylglycylaspartic acid (RGD) are investigated by means of collision-induced-dissociation (CID) and detailed molecular mechanics and density functional theory (DFT) calculations. It is demonstrated that despite the ionizing proton being strongly sequestered at the guanidine group, protonated RGD can easily be fragmented on charge directed fragmentation pathways. This is due to facile mobilization of the C-terminal or aspartic acid COOH protons thereby generating salt-bridge (SB) stabilized structures. These SB intermediates can directly fragment to generate b2 ions or facilely rearrange to form anhydrides from which both b2 and b2+H2O fragments can be formed. The salt-bridge stabilized and anhydride transition structures (TSs) necessary to form b2 and b2+H2O are much lower in energy than their traditional charge solvated counterparts. These mechanisms provide compelling evidence of the role of SB and anhydride structures in protonated peptide fragmentation which complements and supports our recent findings for tryptic systems (Bythell, B. J.; Suhai, S.; Somogyi, A.; Paizs, B. J. Am. Chem. Soc., 2009, 131, 14057–14065.). In addition to these findings we also report on the mechanisms for the formation of the b1 ion, neutral loss (H2O, NH3, guanidine) fragment ions and the d3 ion.
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影响因子：
15
作者：
Bleiholder, Christian;Osburn, Sandra;Paizs, Bela
通讯作者：
Paizs, Bela
影响因子：
2.9
作者：
Bythell, Benjamin J.;Dain, Ryan P.;Van Stipdonk, Michael J.
通讯作者：
Van Stipdonk, Michael J.
影响因子：
2.9
作者：
Bythell, Benjamin J.;Erlekam, Undine;Maitre, Philippe
通讯作者：
Maitre, Philippe
DOI：
10.1016/j.jasms.2005.07.023
发表时间：
2005-12-01
影响因子：
3.2
作者：
Chen, XH;Turecek, F
通讯作者：
Turecek, F
影响因子：
15
作者：
Erlekam, Undine;Bythell, Benjamin J.;Maitre, Philippe
通讯作者：
Maitre, Philippe