Tn antigen

Tn antigen refers to the "oligosaccharide" (in fact monosaccharide) structure N-acetylgalactosamine (GalNAc) linked to serine or threonine by a glycosidic bond, i.e. as an O-glycan. It is not usually found on healthy cell surfaces, but may be found on cancer cells.[1] Addition of single monosaccharide residues creates disaccharide antigens: the Thomsen-Friedenreich antigen (TF antigen or T antigen) is formed by substitution with galactose (Gal(b1-3)GalNAc); the sialyl Tn antigen (STn antigen) is formed by substitution with sialic acid (Neu5Ac(a2-6)GalNAc. Further substitution gives the normal core structures and O-glycans found on healthy cell surfaces.

References

  1. ↑ I. Brockhausen, H. Schachter, P. Stanley, Essentials of Glycobiology, 2nd edition. A. Varki, R. Cummings, J. Esko, Eds, Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press; 2009. Chapter 9, O-GalNAc Glycans