Use of CID/ETD mass spectrometry to analyze glycopeptides.
Use of CID/ETD mass spectrometry to analyze glycopeptides.
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DOI：
10.1002/0471140864.ps1211s68
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发表时间：
2012-04
影响因子：
--
通讯作者：
Mechref, Yehia
中科院分区：
文献类型：
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作者：
Mechref, Yehia
碰撞诱导解离（CID）串联质谱法（MS）不允许对糖肽进行表征，因为其聚糖结构断裂且肽骨架断裂有限。另一方面，电子转移解离（ETD）串联MS提供了一种仅允许糖肽的肽骨架片段化的替代方法。本单元总结了使用CID和ETD对糖肽的表征。虽然CID提供与连接到肽骨架的聚糖部分的组成相关的信息，但ETD允许肽的从头测序，因为它仅促进肽骨架片段化，同时保持翻译后修饰完整。在ETD中观察到自由基阴离子将电子转移到肽骨架，诱导N-Cα键断裂。聚糖部分保留在肽骨架上，基本上不受ETD过程的影响。因此，ETD不仅允许鉴定糖肽的氨基酸序列，还允许明确分配其糖基化位点。当从两种裂解技术获得的数据相结合时，可以全面表征整个糖肽。这是使用能够在LC-MS/MS分析期间在CID和ETD实验之间交替的仪器来实现的。本单元讨论了在CID和ETD中观察到的糖肽的不同片段化。提供了CID中观察到的与氧鎓离子相关的残留物质量表，以帮助解释CID质谱。CID和ETD两者用于更好地表征糖肽的效用被证明用于模型糖蛋白。
Collision-induced dissociation (CID) tandem mass spectrometry (MS) does not allow the characterization of glycopeptides because of the fragmentation of their glycan structures and limited fragmentation of peptide backbones. Electron-transfer dissociation (ETD) tandem MS, on the other hand, offers an alternative approach allowing the fragmentation of only peptide backbones of glycopeptides. Characterization of glycopeptides using both CID and ETD is summarized in this unit. While CID provide information related to the composition of glycan moiety attached to a peptide backbone, ETD permits de novo sequencing of peptides, since it prompts only peptide backbone fragmentation while keeping posttranslational modifications intact. Radical anions transfer of electrons to peptide backbone which induces cleavage of the N-Cα bond is observed in ETD. The glycan moiety is retained on the peptide backbone, largely unaffected by the ETD process. Accordingly, ETD allows not only the identification of the amino acid sequence of a glycopeptide, but also the unambiguous assignment of its glycosylation site. When data acquired from both fragmentation techniques are combined, it is possible to characterize comprehensively the entire glycopeptide. This is achieved using an instrument capable of alternating between CID and ETD experiments during an LC-MS/MS analysis. This unit discusses the different fragmentation of glycopeptides observed in CID and ETD. Tables of residue masses associated with oxonium ions observed in CID are provided to help in the interpretation of CID mass spectra. The utility of both CID and ETD for better characterization of glycopeptides are demonstrated for a model glycoprotein.