Glycan reductive isotope labeling for quantitative glycomics

• Type of Material: Article
• Authors: Baoyun Xia, Emory University; Christa L. Feasley, University of Oklahoma; Goverdhan P. Sachdev, University of Oklahoma; David Smith, Emory University; Richard D. Cummings, Emory University
• Language: English
• Date: 2009-04-15
• Publisher: Elsevier Masson
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2009, Elsevier
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.ab.2009.01.028
• Title of Journal or Parent Work: Analytical Biochemistry
• ISSN: 0003-2697
• Volume: 387
• Issue: 2
• Start Page: 162
• End Page: 170
• Grant/Funding Information: This work was supported in part by NIH Grant HL065509 to GPS and resources from the Glycomics Center at Emory University.
• Keywords: glycans; reductive amination; Mass spectrometry; MALDI; glycoproteins; oligosaccharides
• Research Categories: Chemistry, Biochemistry

Abstract

Many diseases and disorders are characterized by quantitative and/or qualitative changes in complex carbohydrates. Mass spectrometry methods show promise in monitoring and detecting these important biological changes. Here we report a new glycomics method, termed Glycan Reductive Isotope Labeling (GRIL), where free glycans are derivatized by reductive amination with the differentially coded stable isotope tags [12C6]-aniline and [13C6]-aniline. These dual-labeled aniline-tagged glycans can be recovered by reversed-phase chromatography and quantified based on UV-absorbance and relative ion abundances. Unlike previously reported isotopically coded reagents for glycans, GRIL does not contain deuterium, which can be chromatographically resolved. Our method shows no chromatographic resolution of differentially labeled glycans. Mixtures of differentially tagged glycans can be directly compared and quantified using mass spectrometric techniques. We demonstrate the use of GRIL to determine relative differences in glycan amount and composition. We analyze free glycans and glycans enzymatically or chemically released from a variety of standard glycoproteins, as well as human and mouse serum glycoproteins using this method. This technique allows for linear, relative quantitation of glycans over a 10-fold concentration range and can accurately quantify sub-picomole levels of released glycans, providing a needed advancement in the field of Glycomics.