Monoclonal antibodies raised against membrane glycoproteins from mouse brain recognize N-linked oligomannosidic glycans

Monoclonal L3 and L4 antibodies have been shown to recognize carbohydrate epitopes on several neural cell adhesion molecules; these epitopes can be released by treatment with endoglycosidase H. In the present study, we have identified the oligosaccharides released by endoglycosidase H from the cell adhesion molecules AMOG and L1 by fast-atom bombardment mass spectrometry as being solely of the oligomannosidic type. Using neoglycolipids of oligomannosidc glycans, we also report that both antibodies show the highest reactivity with the α-manno-pentaose Manα1-3-[Manα1-6(Manα1-3)Manα1-6]-Man, but decreasing reactivity with the α-manno-hexaose, heptaose, octaose and nonaose glycans. Thus, to our knowledge, we describe here for the first time monoclonal antibodies recognizing N-glycosidically linked oligomannosidic glycans.