Figure 23.

Typical O-glycan structures. (A) The most abundant O-glycan core structures 1–4 and the four less common cores 5–8 shown using the symbol nomenclature for glycans (SNFG). (B) Typical extensions of glycan cores are the attachment of N-acetyllactosamine units, sialylation, and fucosylation. (C) Examples for fully processed O-glycan structures based on core 1 (upper structure) and core 3 (lower structure) including their linkage site to the glycoprotein. At the nonreducing end, O-glycans often contain antigenic structures such as the ABO and Lewis blood group determinants, which are highlighted by gray boxes.