Characteristics of Streptococcal Group-specific Antibody Isolated from Hyperimmune Rabbits

Intravenous immunization of New Zealand red rabbits with streptococcal group-specific bacterial vaccines yielded sera which possessed markedly elevated gamma-globulin. The sera of one rabbit immunized with Group A-variant vaccine possessed 55 mg/ml of gamma-globulin. The bulk of this gamma-globulin, identified as gamma(G)-globulin, was homogeneous by zone electrophoresis and of specificity directed against the Group A-variant carbohydrate antigen. L chains isolated from specific antibody obtained from an immune precipitate were distributed as a single band on starch gel electrophoresis, whereas the normal gamma-globulin traveled as a diffuse smear. These data suggest that the rabbit streptococcal Group A-variant antibodies possess a limited range of physicochemical properties and electrophoretic mobility compared to that generally observed for the normal complement of gamma-globulin.