PREPARATION AND CHARACTERIZATION OF ANTIBODY TO GALACTOSYL(ALPHA-1-]4)GALACTOSYL(BETA-1-]4)GLUCOSYLCERAMIDE

Antiserum against galactosyl(.alpha.1 .fwdarw. 4)galactosyl(.beta.1 .fwdarw. 4)glucosylceramide (globotriaosylceramide, Gb3) was raised in rabbits by the administration of 4 weekly i.m. injections of 1.5 mg of the purified glycolipid along with bovine serum albumin and Freund''s complete adjuvant. Anti-Gb3 activity was quantitated initially by immunoprecipitation employing Gb3 mixed with 100-fold excess of lecithin and cholesterol (1:1 or 1:2, by wt.) as antigen [Ag]. Complement [C] fixation tests done with Ag preparations containing (b3/lecithin/cholesterol (1:6:20, by wt.) showed anti-Gb3 titers of up to 1:8192. Fractionation of the antiserum by BioGel A5m chromatography indicated the antibody [Ab] was Ig(immunoglobulin)M. The partially purified Ab stimulated C-dependent release of glucose from glucose-containing liposomes prepared with sphingomyelin/cholesterol/dicetylphosphate/Cb3 (molar ratio, 100:75:11:1). The Ab crossreacted with the trisaccharide, Gal(.alpha.1 .fwdarw. 4)Gal(.beta.1 .fwdarw. 4)Glc, but not with galactosylceramide, lactosylceramide, GM1 ganglioside, globotetraosylceramide, digalactosyldiglyceride or a number of low MW saccharides.