What are Glycoproteins?

Glycoproteins are proteins carrying specific sugar chains. The early stages of so called N-glycosylation occurring during protein biosynthesis within the cell are highly conserved in all plants and animals studied to date [Link], indicating the high evolutionary significance of these processes. In contrast, the final "furnishing" of these glycan structures has developed in a more species specific manner, hinting towards specialised functions of glycoproteins in different species. More than 50% of human proteins are predicted to be glycosylated [Link], and the involvement of various glycoproteins has been indicated in a variety of diseases such as cancer, inflammation, allergy and many more. Famous examples for important glycoproteins are Immunoglobulins (IgG, IgE, IgM, IgA), Erythropoietin (EPO) or the prion proteins.

Glycoproteins are possibly one of nature's best examples for uniting biomolecules with different characteristics to form a new class of biomolecules. This dual nature of glycoproteins as well as the non-template driven glycan biosynthesis pose certain challenges in the analysis of glycoproteins and make Glycoproteomics a new exciting frontier in postgenomics standing between the well established Proteomics community and the traditional glycoanalytics field. Having one foot in the Glycomics and one in the Proteomics world Glycoproteomics presents itself as an interdisciplinary science that aims at the better understanding of the biological role of glycoproteins.

Mass Spectrometry based methods have developed as the major tools in the sensitive and comprehensive characterisation of biomolecules like proteins and glycoproteins. The enormous developmental progress these techniques experienced in recent years laid the analytical basis for the arise of sciences like Proteomics, Glycomics and Glycoproteomics. The sophisticated combination of various sample preparation and separation techniques with different mass spectrometry approaches has enabled new insights in biomolecules leading equally to both, new knowledge and new challenges in the quest of understanding the underlying biochemical code of life.