New Advances in the Understanding of the In-Source Decay Fragmentation of Peptides in MALDI-TOF-MS
New Advances in the Understanding of the In-Source Decay Fragmentation of Peptides in MALDI-TOF-MS
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DOI：
10.1016/j.jasms.2010.07.009
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发表时间：
2010-11-01
影响因子：
3.2
通讯作者：
De Pauw, Edwin Andre
中科院分区：
文献类型：
--
作者：
Demeure, Kevin;Gabelica, Valerie;De Pauw, Edwin Andre
源内衰变（ISD）是基质辅助激光解吸电离（MALDI）源在离子引出前发生的快速碎裂。尽管通过ISD对肽从头测序的兴趣越来越大，但基质和肽本身的影响尚未完全理解。在这里，我们比较了具有高ISD效率的矩阵，以更深入地了解ISD碎片化过程。主要的ISD片段是c-和z-离子，但也观察到其他类型的片段，并在这里研究它们的起源。两种主要途径导致源中的碎裂：导致c-、z-、w-和d-离子的自由基诱导途径，以及导致y-、B-和a-离子的热活化途径。对所选肽的ISD光谱的详细分析显示：（1）两种源内途径的程度取决于所用的基质而不同，（2）自由基诱导的片段上存在正/负电荷是分别以正/负模式观察它们所必需的，以及（3）对于同一肽，不同类型片段的图案根据所使用的矩阵而不同。（J Am Soc Mass Spectrom 2010，21，1906-1917）（C）2010年美国质谱学会
In-source decay (ISD) is a rapid fragmentation occurring in the matrix-assisted laser desorption/ionization (MALDI) source before the ion extraction. Despite the increasing interest for peptides de novo sequencing by ISD, the influence of the matrix and of the peptide itself is not yet fully understood. Here we compare matrices with high ISD efficiencies to gain deeper insight in the ISD fragmentation process(es). The major ISD fragments are the c- and z-ions, but other types of fragments are also observed, and their origin is studied here. Two main pathways lead to fragmentation in the source: a radical-induced pathway that leads to c-, z-, w-, and d-ions, and a thermally activated pathway that leads to y-, b-, and a-ions. A detailed analysis of the ISD spectra of selected peptides revealed that (1) the extents of the two in-source pathways are differently favored depending on the matrix used, that (2) the presence of a positive/negative charge on the radical-induced fragments is necessary for their observation in positive/negative mode, respectively, and that (3), for a same peptide, the patterns of the different types of fragments differ according to the matrix used. (J Am Soc Mass Spectrom 2010, 21, 1906-1917) (C) 2010 American Society for Mass Spectrometry