Localization of O-glycosylation sites in peptides by electron capture dissociation in a fourier transform mass spectrometer
Localization of O-glycosylation sites in peptides by electron capture dissociation in a fourier transform mass spectrometer
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DOI：
10.1021/ac990578v
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发表时间：
1999-10-15
影响因子：
7.4
通讯作者：
Zubarev, RA
中科院分区：
文献类型：
--
作者：
Mirgorodskaya, E;Roepstorff, P;Zubarev, RA
电喷雾产生的[M + nH]nt多肽阳离子的新技术电子捕获解离（ECD）产生骨架NH-C1键的快速裂解以形成c和z离子（在Roepstorff和Fohlman的修改的符号中）。本文研究了配备电子捕获检测器的傅里叶变换质谱法在3 kDa范围内O-糖基化肽结构分析中的潜力。总的来说，85%的可用残基间键被裂解在5个糖肽，更稳定的C离子占62%的观察到的碎片。c系列提供了糖基化位点的直接证据：在研究的每种情况下，从这些物质中未观察到聚糖（GalNAc和二甘露糖）损失。较不稳定的Z离子支持聚糖位点分配，具有次要聚糖：determinate。这些损失，以及所观察到的偶数电子z离子的形成，归因于自由基网站引发的反应。在有利的情况下，从单扫描光谱获得完整的序列和聚糖位置信息。ECD的“温和”特征支持先前提出的非遍历（能量随机化之前的裂解）机制，以及：片段的低内能增量。
The novel technique electron capture dissociation (ECD) of electrospray generated [M + nH]nt polypeptide cations produces rapid cleavage of the backbone NH-C, bond to form c and z ions (in the modified notation of Roepstorff and Fohlman). The potential of the Fourier transform mass spectrometry equipped with ECD in structure analysis:of O-glycosylated peptides in the 3 kDa range has been investigated. Totally, 85% of the available interresidue bonds were cleaved in five glycopeptides; more stable c ions accounted for 62% of the observed fragmentation. The c series provided direct evidence on the glycosylation sites:in every case studied, with no glycan (GalNAc and dimannose) losses observed from these species. Less stable z lions Supported the glycan site assignment, with minor glycan,: detachments. These losses, as well as the observed formation of even-electron z ions, are attributed to radical-site-initiated reactions. In favorable cases, complete sequence and glycan position information is obtained from a single-scan spectrum. The "mild" character of ECD supports the previously proposed nonergodic (cleavage prior to energy randomization) mechanism, and the:low internal energy increment of fragments.