Irungu Janet, Go Eden P, Dalpathado Dilusha S, Desaire Heather
Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
Anal Chem. 2007 Apr 15;79(8):3065-74. doi: 10.1021/ac062100e. Epub 2007 Mar 10.
Mass spectral analysis is an increasingly common method used to characterize glycoproteins. When more than one glycosylation site is present on a protein, obtaining MS data of glycopeptides is a highly effective way of obtaining glycosylation information because this approach can be used to identify not only what the carbohydrates are but also at which glycosylation site they are attached. Unfortunately, this is not yet a routine analytical approach, in part because data analysis can be quite challenging. We are developing strategies to simplify this analysis. Presented herein is a novel mass spectrometry technique that identifies the peptide moiety of either sulfated, sialylated, or both sialylated and sulfated glycopeptides. This technique correlates product ions in collision-induced dissociation (CID) experiments of suspected glycopeptides to a peptide composition using a newly developed web-based tool, GlycoPep ID. After identifying the peptide portion of glycopeptides with GlycoPep ID, the process of assigning the rest of the glycopeptide composition to the MS data is greatly facilitated because the "unknown" portion of the mass assignment that remains can be directly attributed to the carbohydrate component. Several examples of the utility and reliability of this method are presented herein.
质谱分析是一种用于表征糖蛋白的日益常见的方法。当蛋白质上存在多个糖基化位点时，获取糖肽的质谱数据是获得糖基化信息的一种非常有效的方法，因为这种方法不仅可以用于识别碳水化合物是什么，还可以识别它们连接在哪个糖基化位点上。不幸的是，这尚未成为一种常规的分析方法，部分原因是数据分析可能颇具挑战性。我们正在开发简化这种分析的策略。本文介绍了一种新型质谱技术，该技术可识别硫酸化、唾液酸化或同时硫酸化和唾液酸化的糖肽的肽部分。该技术使用新开发的基于网络的工具GlycoPep ID，将疑似糖肽的碰撞诱导解离（CID）实验中的产物离子与肽组成相关联。使用GlycoPep ID识别糖肽的肽部分后，将糖肽组成的其余部分分配到质谱数据的过程会大大简化，因为质量分配中剩余的“未知”部分可以直接归因于碳水化合物成分。本文给出了该方法实用性和可靠性的几个例子。
