Glycomic analysis of N-linked carbohydrate epitopes from CD24 of mouse brain.

Murine CD24 is an abundantly glycosylated glycoprotein that plays important roles in the central nervous system and the immune system. It has been proposed that the functions of CD24 are primarily mediated by its N- and/or O-linked glycans. Applying a highly sensitive glycomics approach which included matrix-assisted laser-desorption ionization and electrospray ionization ion trap mass spectrometry, we have performed a detailed analysis of the N-linked glycans of CD24. Our data revealed a highly heterogeneous pattern of mainly complex type glycans expressing distinct carbohydrate epitopes, like 3-linked sialic acid, Le(X) or blood group H antigens, bisecting N-acetylglucosamine residues and N-acetyllactosamine repeats as well as high-mannose and hybrid type species.