A procedure for the analysis of site-specific and structure-specific fucosylation in alpha-1-antitrypsin

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• 作者：Haidi Yin ; Jianhui Zhu ; Jing Wu ; Zhijing Tan ; Mingrui An ; Shiyue Zhou ; Yehia Mechref and David M. Lubman
• 刊名：ELECTROPHORESIS
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：37
• 期：20
• 页码：2624-2632
• 全文大小：936K
• ISSN：1522-2683

文摘

A MS-based methodology has been developed for analysis of core-fucosylated versus antennary-fucosylated glycosites in glycoproteins. This procedure is applied to the glycoprotein alpha-1-antitrypsin (A1AT), which contains both core- and antennary-fucosylated glycosites. The workflow involves digestion of intact glycoproteins into glycopeptides, followed by double digestion with sialidase and galactosidase. The resulting glycopeptides with truncated glycans were separated using an off-line HILIC (hydrophilic interaction liquid chromatography) separation where multiple fractions were collected at various time intervals. The glycopeptides in each fraction were treated with PNGase F and then divided into halves. One half of the sample was applied for peptide identification while the other half was processed for glycan analysis by derivatizing with a meladrazine reagent followed by MS analysis. This procedure provided site-specific identification of glycosylation sites and the ability to distinguish core fucosylation and antennary fucosylation via a double digestion and a mass profile scan. Both core and antennary fucosylation are shown to be present on various glycosites in A1AT.