Characterization of Complexes Which Contain Diphtheria Toxin and Human Nonprecipitating Antitoxin

[摘要] Complexes which contained nonprecipitating diphtheria antitoxin and I131 toxin were analyzed for sedimentation behavior in the ultracentrifuge. When high-speed centrifugation was employed using a separation cell, it was found that sedimentation of the complex was fastest at six-fold antibody excess and slowest at antibody equivalence as judged by relative percentages of I131 in upper and lower portions of the cell. When studied electrophoretically using the technique of zone electrophoresis, it was found that complexes at equivalence or in antibody excess remained close to the point of application, but migrated toward the anode when in antigen excess. Approximate sedimentation constants for the different toxin-antitoxin combinations are presented. The use of labelled antigens and physicochemical methods in the purification of nonprecipitating antibody are discussed.

[学科分类] 生物科学（综合）