Linkage (Methylation) Analysis
Linkage (methylation) analysis is used in the analysis of glycoproteins and carbohydrates to determine the identities of the various linkages between the monosaccharides present. This information can be used at all stages of drug development.
In conjunction with oligosaccharide population analysis, it can provide a detailed picture of the glycans present and identify specific linkages that may be of functional importance e.g. 3- versus 6-linked sialic acid (which can have a significant impact on activity), or the presence of multiantennary structures versus lactosamine repeats, which can be isobaric (e.g. disialylated biantennary glycan with lactosamine repeat versus disialylated triantennary glycan). It can also be used to demonstrate consistency between batches for release during the manufacturing process.
Linkage analysis is a powerful technique in glycoprotein analysis. It can be used for:
- Screening of glycoproteins manufactured using different cell lines.
Linkage analysis is performed using Gas Chromatography-Mass Spectrometry (GC-MS).
Linkage analysis is a key part of the requirements laid out in the ICH Q6B guidelines for characterisation and confirmation of biopharmaceuticals in support of new marketing applications.