Orbitrap Illustration

PTM Glycosylation

Nearly all proteins undergo chemical modifications after translation. These post-translational modifications (PTMs) play crucial roles in functional proteomics, regulating the protein structure, activity, and expression. PTMs regulate interaction with cellular molecules such as nucleic acids, lipids and cofactors, as well as other proteins. PTMs can occur at any moment in the "life cycle" of a protein, influencing their biological function in processes such as initiating catalytic activity, governing protein-protein interactions, or causing protein degradation. Glycosylation and phosphorylation are of particular interest to researchers because they are critical pathways for signaling, activation, and often give insight into disease states.

Analysis of PTMs by mass spectrometry using multiple fragmentation techniques yields the most comprehensive structural characterization of modified proteins. Here we describe useful workflows for analysis of glycosylated and phosphorylated proteins.

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View the related workflows for
Glycan Analysis


Workflow Overview for Glycosylation


Glycosylation is likely the most common PTM. It is known to play a role in biochemical processes, ranging from mediation of cell interactions to defining cellular identities within complex tissues.1,2 In addition, glycan structures are unique to the proteins and help to regulate the protein activity. Many glycans undergo disease-related expression level changes, potentially providing critical diagnostic information.3,4 Mass spectrometry (MS) has emerged as one of the most powerful tools for structural elucidation of glycosylations due to its sensitive detection and ability to analyze complex mixtures derived from a variety of organisms and cell lines. Sample enrichment, MS acquisition strategy and data analysis must all be optimized to ensure successful glycoproteomics experiments.





1. The Potentials of Glycomics in Biomarker Discovery

Miura Y, Hato M, et al.
Mol Cell Proteomics. 2008 Feb;7(2):370-7.


2. Glycomics: a pathway to a class of new and improved therapeutics

Shriver Z, Raguram S, et al.
Nat Rev Drug Discov. 2004 Oct;3(10):863-73.

3. Altered Glycosylation of Surface Glycoproteins in Tumor Cells and its Clinical Application

Kobata A.
Pigment Cell Res. 1989 Jul-Aug;2(4):304-8.

4. Glycosylation defining cancer cell motility and invasiveness

Ono M, Hakomori S.
Glycoconj J. 2004;20(1):71-8.