Preparation and Properties of Antibodies to GD3 and GM1 Gangliosides

Abstract: Gangliosides G_D3 and G_M1 were coupled to proteins by their car-boxyl groups and antisera were raised against the complexes. Anti-ganglioside antibodies were isolated by affinity chromatography on ganglioside-amino-propyl silica gel columns and the specificity of the antibodies was determined by a quantitative microcomplement fixation assay. Antibodies to G_D3 were highly specific and did not crossreact with G_M3, lactosyl ceramide, or other glycolipids. Purified antibodies to G_M1, in contrast, crossreacted with asialo-G_M1, G_D1b and to a lesser extent, G_M2 and asialo-G_M2. A derivative of G_M1, containing a C-7 sialic acid residue produced by periodate oxidation, reacted with the anti-G_M1 antibodies almost as readily as with G_M1. The specificities of anti-G_M1 antibodies elicited by the covalent ganglioside-protein complexes were similar to those produced by immunization with noncovalent complexes of G_M1 and methylated bovine serum albumin. The ganglioside-protein complexes described here should be useful for preparing antibodies to polysialo-gangliosides that contain neuraminidase-sensitive linkages.