National Physical Laboratory

Post-translational modification analysis

Post-translational modification analysis 

One of the most common post-translational modifications of proteins is glycosylation, which can be analysed using a range of physico-chemical techniques available at NPL. Underivatised or fluorophore-labelled oligosaccharides are isolated and analysed by a range of chromatographic and mass spectrometric techniques to identify and quantify the relative molar amount of each structure present. Charge profiling to determine the degree of sialylation is also routinely carried out.

Oligosaccharide composition can be analysed by fragmentation approaches similar to those described for peptides (using LC-MS/MS). The molecular weights of the fragment ions can then be used to reconstruct the sequence of sugar residues in the parent structure. Knowledge of the biosynthetic pathways of glycans can aid in the interpretation of chromatographic profiles and mass spectra.

The Biotechnology group also has experience in detecting other common modifications to proteins such as deamidation of asparagine and glutamine amino acid residues and oxidation of methionine residues. These modifications have been demonstrated to have significant effects on protein structure and function, and are therefore of concern to any manufacturers of proteins for therapeutic or diagnostic use.


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Last Updated: 18 Aug 2015
Created: 6 May 2009


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