Preparation and properties of antibodies to GD3 and GM1 gangliosides

Abstract

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.