Antibodies to Glycans

Glycosylation is a posttranslational modification that creates a vast repertoire of structural and functional diversity on proteins.  Glycosylated proteins (glycoproteins) and other glycoconjugates occur in all compartments of the living cell, and carbohydrate structures are of particular importance on the cell surface where they mediate fundamental processes underlying cell-cell and cell-matrix interactions, cell-proliferation, and infection. Complex carbohydrate is being elaborated on glycoproteins and proteoglycans as linear or branched chains of monosacchardie units known as glycans. Specific glycans are known to underly important biomedical phenomena, such as blood hemostasis, cell-adhesion, viral infection (influenza, herpes simplex), and embryonic development.

Glycans have been known to pose seriuos challenges to antibody development. They are usually not or only weakly immunogenic, and they cannot be processed by antigen-presenting cells to create a T-helper response. Therefore, carbohydrate specific antibodies normally arise, if at all, only as low affinity IgMs. However, recently new technologies have been developed that allow generation of high affinity IgG type antibodies to complex glycans. These involve chemoenzymatic synthesis of glycan substructures in conjunction with novel immunogenic carrier proteins or peptides and immunization of transgenic mice that are missing the gene encoding one or the other glycosyl transferase enzyme required for biosynthesis of the glycan of interest. Important antibodies to glycans include antibodies to the blood group antigens and 2G12, one of the few antibodies able to neutralize human immunodeficiency virus regardless of mutational state.

Antibody Solutions is very familiar with the concept of glycan specific antibodies. For example, we custom made a rabbit antiserum that recognized terminal N-acetylglucosamine 6-sulfate and did not bind significantly to unsulfated N-acetylglucosamine. For the same group of researchers we also made a monoclonal IgM known as MECA-79 that is specific to a sulfated N-acetyllactosamine epitope on sulfoadhesin, a family of complex glycans implicated in chronic inflammatory diseases. This antibody is commonly used in immunohistochemistry of inflamed lesions in human and animal models (right image).

Antibody Solutions
Tel: 888-843-1069 Fax: 650-938-4390 E-mail: