Anti-glycosyl antibodies. Two sets of isoantibodies with specificity for different carbohydrate moieties of the same glycosyl antigen.

Two sets of anti-glycosyl antibodies have been isolated by affinity chromatography methods from the antisera of rabbits immunized with a vaccine of nonviable cells of Streptococcus faecalis, strain N. Both types of antibodies are directed against a dineteroglycan of glucose and galactose present in the cell wall of this organism. The members of one set, anti-galactose antibodies, combine with the terminal lactose residues of the glycan and the member of the other set, anti-lactose antibodies, combine with terminal lactose residues of the same glycan. Each set of antibodies is composed of multiprotein components. The electrofocusing method had been used to isolate the individual antibody proteins in homogeneous states as shown by both electrophoresis and ultracentrifugation techniques. Since the components of each set combine with the same structural unit of the antigen, they have been designated as isoantibodies. The sedimentation constants, electrophoretic properties, carbohydrate constituents, and amino acid compositions of the two sets of antibodies are recorded.