Glycoprotein Function

Analysis of the SWISS-PROT database indicated that more than half of all proteins are glycosylated and glycosylation is widely distributed in all species. In all eukaryotic cells, one of the most important and common post-translational modifications to proteins is the covalent addition of carbohydrates. There are various types of carbohydrate-protein linkage, involving the most known monosaccharides and functional groups of amino acid chains. The protein-linked monosaccharides are usually extended by the attachment of other monosaccharides that give multiple oligosaccharide structures. Therefore, the function of glycoproteins is diverse due to structural complexity. Base on the rich experience and mature technology, Creative Biolabs launched comprehensive and rapid glycoprotein-related services including custom synthesis, expression, analysis, vaccine development, and glyco-diag. We guarantee to offer excellent service and competitive products to meet every requirement in your programs.

Introduction of Glycoprotein Function

Fig.1 Glycoproteins in multiple mechanisms of
cellular regulation. (Defaus, 2014)

The great variability of protein-linked glycan structures is dictated by tissue-specific regulation of genes encoding enzymes involved in the glycosylation process, availability of the reaction components in the Golgi, competition between glycosyltransferases for acceptor during glycan elongation, and finally by the structure of the glycosylated polypeptide and microenvironment of the growing glycan chain. The differences in glycan structures exist not only between different glycoproteins but also between molecules of individual glycoprotein produced by the same cells and between different glycosylation sites of one molecule, which results in various protein glycoforms, while further leading to various functions.

The functions of glycoproteins are diverse, spanning a wide range of vital biological activities. Almost all the proteins of plasma, contain sugar chains and fulfill such varied roles as transport, clotting, and antibody activity. Gonadotropins from both pituitary and placental origin are glycoproteins, as are thyroid-stimulating hormone and thyroglobulin, the thyroid hormone storage protein. A rapidly increasing number of proteins with enzyme activity, including various hydrolases, oxidases, and transferases, are being reported as glycoproteins. The protective and lubricating roles of the glycoproteins from epithelial secretions are well known. It is evident now that the members of the large collagen family are glycoproteins and that they along with the proteoglycans and various soluble glycoproteins make up the bulk of the intercellular matrix which provides structural support to multicellular organisms. Extracellular structures such as basement membranes and cell walls, serve as supportive elements and may also function in the capacity of coarse sieves. While the glycoprotein components of the cell membranes have the most intriguing function in the active transport of molecules, they also serve as receptors for viruses, hormones, and antibodies, and take part in intercellular recognition and adhesion.

Fig.2 Organization of the SARS-CoV-2 S glycoprotein with N-linked glycans. (Walls, 2020)

While the biological functions of glycoproteins are important, the role which the carbohydrate plays in helping these proteins carry out their activities is not totally clear. Therefore, Creative Biolabs established a one-stop glycoproteins research platform to support the programs for global clients. To learn more about the function of glycoproteins, please click follow key words or contact us directly.

References

Defaus, S.; et al. Mammalian protein glycosylation-structure versus function. Analyst. 2014, 139(12), 2944-2967.
Walls, A.C.; et al. Structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein. Cell. 2020, 181(2), 281-292.

For Research Use Only.

Glycoprotein Function

Introduction of Glycoprotein Function

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