Introduction
Glycosylation is one of the most prominent and widely studied protein post-translational modifications in nature.
Analysis and characterization of glycoproteins is an important step in correlating glycosylation structures with
their biological activity. However, traditional proteomic studies at the peptide level rarely characterize intact
glycopeptides (glycosylated peptides from which glycans have not been removed), and thus do not retain information
on glycoprotein heterogeneity. Glycopeptide analysis is a new method to analyze the structure of glycoproteins,
without releasing the oligosaccharide chains from the protein, but to characterize the glycopeptides after
proteolysis of the glycoproteins. The main attractive feature of this approach is the ability to associate
glycosylation information with the exact location and glycosylation site on the protein. Glycopeptide analysis is
typically performed during the sample preparation and MS analysis steps, enabling N/O-linked glycopeptides and
mixtures of peptides to be obtained directly during protease digestion without releasing glycans.
Fig. 1.
Overall workflow of Intact glycopeptide characterization using mass spectrometry. (Cao L, et al., 2016)
Our Services
As the world's leading service provider in the field of mass spectrometry, Creative Proteomics
provides comprehensive, one-stop glycopeptide analysis services for global customers. This analysis strategy keeps
glycans linked to their amino acids, enabling simultaneous elucidation of glycopeptide sequences, glycosylation
sites, and glycan composition.
In bottom-up proteomics research, a single protein or the whole protein of a complex biological sample is usually
enzymatically digested into peptides and then identified and quantified by HPLC-MS/MS. However, since the abundance
of glycopeptides in the digestion mixture is usually low, in order to improve the sensitivity of mass spectrometry
analysis. Our scientists will choose the best enrichment method, including hydrophilic interaction chromatography,
lectin affinity, hydrazide chemistry, affinity enrichment, for pretreatment according to the characteristics of your
sample.
At Creative Proteomics, our scientists develop a complete workflow for the glycopeptide analysis.
You only need to tell us the purpose of your experiment and send your samples to us, we will take care of all the
follow-up matters of the project.
Simple experimental procedure for glycopeptide analysis service.
- Enzymatic digestion: An enzyme, usually trypsin or other nonspecific enzymes, including pronase E or proteinase
K.
- Glycopeptide enrichment: The best glycopeptide enrichment method is choosen for a general or specific type of
glycopeptide.
- Mass Spectrometry: After the complete glycopeptide is separated and enriched, it enters a high-resolution mass
spectrometer to obtain a spectrum rich in fragment ions.
- Bioinformatics analysis: Comprehensive analysis with the help of various bioinformatics analysis software such
as ByOnic.
Applications of Glycopeptide Analysis
- Diagnosis or prevention of disease: Comparative glycopeptide analysis of endogenous compounds to differentiate
disease states from healthy states, or to better understand disease progression and pathology.
- Expression of recombinant glycoproteins: Characterizing the glycosylation of therapeutic glycoproteins is an
important way for manufacturers to monitor the batch-to-batch consistency of their manufacturing process, and
these analyzes also help differentiate biosimilars, such as generic versions of therapeutic proteins.
- Drug discovery: Glycopeptide analysis of proteins can be used to develop 3D models of intact proteins, including
glycoforms that determine the properties of glycoproteins. These studies were performed using trypsin digestion
and HPLC-MS, MS/MS, and MALDI-TOF MS on high-resolution instruments.
Advantages of Our Glycosphingolipid Analysis Services
- High quality and precision.
- High sensitivity.
- Professional advice directly from our glycosphingolipid analysis scientists.
- Fast turnaround time.
- Customized services according to your samples types and requirements.
The ICH Q6B guideline requires comprehensive characterization of glycoprotein glycosylation. With an established
glycoprotein research platform and mature support technologies, Creative Proteomics launches
one-stop glycopeptide analysis services to accelerate your project. Additionally, we can provide fully custom
project designs to meet any specific requirements. If you are interested, please contact us or send us an inquiry directly.
References
- Cao L, Qu Y, Zhang Z, et al. (2016) Intact glycopeptide characterization using mass spectrometry.
Expert Rev Proteomics. 13(5):513-22.
- Dalpathado D S, Desaire H. (2008) Glycopeptide analysis by mass spectrometry. Analyst. 133(6):731-8.
