Human Myelin/Oligodendrocyte Glycoprotein: A New Member of the L2/HNK‐1 Family

Abstract— Myelin/oligodendrocyte glycoprotein (MOG) is a quantitatively minor component of CMS myelin. In this study, human MOG was found to express the L2/HNK‐1 epitope on N‐linked oligosaccharide structures. This carbohydrate epitope has been found previously in three other characterized human myelin glycoproteins: the my‐elin‐associated glycoprotein, P₀, and the oligodendrocyte‐myelin glycoprotein. It seems, therefore, that the L2/HNK‐1 epitope is expressed frequently in human myelin glycoproteins. Serial lectin affinity chromatography of ¹⁴C‐glycopeptides indicated that MOG N‐oligosaccharide structures are mainly of the complex type, accounting for 77.8% of total radioactivity. In contrast with myelin‐asso‐ciated glycoprotein and P₀, which express the L2/HNK‐1 epitope on fucosylated structures, in MOG the epitope was detected on all glycopeptide fractions obtained by serial lectin affinity chromatography, although a preferential expression of the L2/HNK‐1 epitope was observed on fucosylated structures. Finally, the data indicated that, as for other human myelin glycoproteins, only a subpopulation of MOG molecules expresses the L2/HNK‐1 epitope.