Have you analyzed all possible glycosylation?

O-linked glycosylation is often overlooked. Researchers tend to focus on N-linked glycosylation analysis, simply because it is more straightforward. O-linked glycans are usually a lot smaller and can be attached to a much wider range of amino acids, so it’s difficult to pinpoint their exact locations.

In recent years, we have put a lot of effort into expanding our abilities and go to great lengths to look at O-linked glycans properly. We’ve developed specific methodologies for the biopharmaceutical industry, meaning you’ll get a purpose-built research program.

For example, you might come to us to determine the structure and heterogeneity of protein glycosylation, either for the entire protein or for each potential glycosylation site. We’ll commence this type of research with liquid chromatography or mass spectrometry.

Or you might be looking for the sites of glycan attachment in your proteins, which we’ll identify by peptide mapping or MALDI-ISD, depending on your needs and budget.

Note that we combine the information we gain with other glycosylation properties, such as sialic acid content and information gained through monosaccharide analysis, to give you a complete overview of the glycans in your protein.

Analyzing protein glycosylation is a key requirement of ICH Q6B.

Technical information

O-linked glycans are a common feature of many glycoproteins, such as EPO, Factor VIII or growth factors and occur in the Golgi apparatus.

Even though they are not necessarily as structurally complicated as in N-linked glycosylation, O-linked glycans can be incredibly diverse. Also, they may attach themselves to proteins at many more possible sites, which increases the complexity of analysis.

O-linked glycans are released by enzymatic digestion or chemical means and we look at them  directly by HPAEC-PAD, or after labelling or permethylation by MALDI-MS or LC-ESI-MS. The method will depend on your research question. The structural heterogeneity of a glycoprotein can be visualized using 2D PAGE or intact mass.

Your contact for O-linked Glycosylation at Protagen Protein Services GmbH