Preparation and properties of antibodies to GD3 and GM1 gangliosides.

Gangliosides GD3 and GM1 were coupled to proteins by their carboxyl groups and antisera were raised against the complexes. Anti-ganglioside antibodies were isolated by affinity chromatography on ganglioside-aminopropyl silica gel columns, and the specificity of the antibodies was determined by a quantitative microcomplement fixation assay. Antibodies to GD3 were highly specific and did not crossreact with GM3, lactosyl ceramide, or other glycolipids. Purified antibodies to GM1, in contrast, crossreacted with asialo-GM1, GD1b, and, to a lesser extent, GM2 and asialo-GM2. A derivative of GM1, containing a C-7 sialic acid residue produced by periodate oxidation, reacted with the ani-GM1 antibodies almost as readily as with GM1. The specificities of anti-GM1 antibodies elicited by the covalent ganglioside-protein complexes were similar to those produced by immunization with noncovalent complexes of GM1 and methylated bovine serum albumin. The ganglioside-protein complexes described here should be useful for preparing antibodies to polysialogangliosides that contain neuraminidase-sensitive linkages.