Related Experiment Video
Updated: Apr 17, 2026

Metabolic Glycoengineering of Sialic Acid Using N-acyl-modified Mannosamines
Published on: November 25, 2017
Characterizing sialic acid variants at the glycopeptide level
Katalin F Medzihradszky1, Krista Kaasik, Robert J Chalkley
1Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco , 600 16th Street Genentech Hall, N474A, Box 2240, San Francisco, California 94158-2517, United States.
This study characterizes sialylated glycopeptides from mouse liver using collision-induced dissociation (CID) and electron-transfer dissociation (ETD) fragmentation. Findings reveal how sialic acid modifications impact glycopeptide identification and chromatographic behavior.
Area of Science:
- Proteomics
- Glycomics
- Mass Spectrometry
Background:
- Glycopeptides play crucial roles in biological processes.
- Characterizing complex glycopeptides, especially sialylated ones, remains challenging in proteomics.
Purpose of the Study:
- To illustrate characteristic fragmentation patterns of differentially sialylated glycopeptides.
- To investigate the impact of sialic acid composition on glycopeptide chromatographic retention.
- To demonstrate a method for identifying glycopeptides using diagnostic oxonium ions.
Main Methods:
- Beam-type collision-induced dissociation (CID) of intact glycopeptides.
- Electron-transfer dissociation (ETD) fragmentation.
- Reverse-phase high-performance liquid chromatography (RP-HPLC).
- Data analysis using MS-Filter in Protein Prospector.
Main Results:
- Eight glycoforms of an O-linked glycopeptide from Nucleobindin-1 were distinguished.
- Sialic acid variants showed neutral loss in ETD fragmentation.
- Sialic acid addition increased retention times; N-glycolyl and O-acetyl modifications altered retention differently.
- MS-Filter successfully identified various glycopeptides in a phosphopeptide dataset.
Conclusions:
- Fragmentation patterns and chromatographic behavior provide insights into sialylated glycopeptide structure.
- Diagnostic oxonium ions are valuable for glycopeptide discovery in mass spectrometry data.
- This approach enhances the identification of complex glycopeptides in biological samples.
More Related Videos
13:36Author Spotlight: Dendritic Cells Maturation Using Sialidases-Based Enzymatic Treatment of the Cell Surface
Published on: October 20, 2023
08:37The Application of Open Searching-based Approaches for the Identification of Acinetobacter baumannii O-linked Glycopeptides
Published on: November 2, 2021
Related Concept Videos
Protein Glycosylation
Glycosylation occurs in...
Proteoglycans
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Peptidoglycan Synthesis
Glycosaminoglycans
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
Glycocalyx and its Functions