Comparative glycomic profiling of isotopically permethylated N‐glycans by liquid chromatography/electrospray ionization mass spectrometry. (12th March 2013)

• Record Type: Journal Article
• Authors: Hu, Yunli; Desantos‐Garcia, Janie L.; Mechref, Yehia
• Is Part Of: Rapid communications in mass spectrometry. Volume 27:Number 8(2013)
• Page Start: 865
• Page End: 877
• Publication Date: 2013-03-12
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.6512
• Languages: English
• ISSNs: 0951-4198

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="rcm6512-sec-0001" sec-type="section"> <title>RATIONALE</title> <p>Mass spectrometry based comparative glycomics is essential for disease biomarker discovery. However, developing a reliable quantification method is still a challenging task.</p> </sec> <sec id="rcm6512-sec-0002" sec-type="section"> <title>METHODS</title> <p>We here report an isotopic labeling strategy employing stable isotopic iodomethane for comparative glycomic profiling by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS). N‐Glycans released from model glycoproteins and blood serum samples were permethylated with iodomethane ('light') and iodomethane‐<italic>d</italic><sub>1</sub> or ‐<italic>d</italic><sub>3</sub> ('heavy') reagents. Permethylated samples were then mixed at equal volumes prior to LC/ESI‐MS analysis.</p> </sec> <sec id="rcm6512-sec-0003" sec-type="section"> <title>RESULTS</title> <p>Peak intensity ratios of N‐glycans isotopically permethylated (Heavy/Light, H/L) were almost equal to the theoretical values. Observed differences were mainly related to the purity of 'heavy' iodomethane reagents (iodomethane‐<italic>d</italic><sub>1</sub> or ‐<italic>d</italic><sub>3</sub>). The data suggested the efficacy of this strategy to simultaneously quantify N‐glycans derived from biological samples representing different cohorts. Accordingly, this strategy is effective in comparing multiple samples in a single LC/ESI‐MS analysis. The potential of this strategy for defining glycomic differences in blood serum samples representing different esophageal diseases was explored.</p> </sec> <sec id="rcm6512-sec-0004" sec-type="section"> <title>CONCLUSIONS</title> <p>LC/ESI‐MS comparative glycomic profiling of isotopically permethylated N‐glycans derived from biological samples and glycoproteins reliably defined glycan changes associated with biological conditions or glycoproteins expression. As a biological application, this strategy permitted the reliable quantification of glycomic changes associated with different esophageal diseases, including high grade dysplasia, Barrett's disease, and esophageal adenocarcinoma. Copyright © 2013 John Wiley & Sons, Ltd.</p> </sec> </abstract>