Mass Spectrometric Analysis of Sialylated Glycans with Use of Solid-Phase Labeling of Sialic Acids

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• 作者：Punit Shah ; Shuang Yang ; Shisheng Sun ; Paul Aiyetan ; Kevin J. Yarema ; Hui Zhang
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：April 2, 2013
• 年：2013
• 卷：85
• 期：7
• 页码：3606-3613
• 全文大小：389K
• 年卷期：v.85,no.7(April 2, 2013)
• ISSN：1520-6882

文摘

The analysis of sialylated glycans is critical for understanding the role of sialic acid in normal biological processes as well as in disease. However, the labile nature of sialic acid typically renders routine analysis of this monosaccharide by mass spectrometric methods difficult. To overcome this difficulty we pursued derivatization methodologies, extending established acetohydrazide approaches to aniline-based methods, and finally to optimized p-toluidine derivatization. This new quantitative glycoform profiling method with use of MALDI-TOF in positive ion mode was validated by first comparing N-glycans isolated from fetuin and serum and was then exploited to analyze the effects of increased metabolic flux through the sialic acid pathway in SW1990 pancreatic cancer cells by using a colabeling strategy with light and heavy toluidine. The latter results established that metabolic flux, in a complementary manner to the more well-known impact of sialyltransferase expression, can critically modulate the sialylation of specific glycans while leaving others virtually unchanged.