Comparative investigations of purified diphtheria and tetanus T-components and their fragments

Abstract 1. By means of Rivanol ® , ammonium sulphate and zone electrophoresis it was possible to isolate highly purified T -components from tetanus- and diphtheria-horse hyperimmune sera which sediment in the ultracentrifuge homogeneously with S 7. The 7 S T -components were digested with pepsin to homegeneous 5 S fragments from which by reduction with mercaptoethanol and fractionation on Sephadex 3.5 S fragments were obtained. 2. From the 7 S preparations and the fragments amino acid, carbohydrate analyses and fingerprints were made. They showed differences between the 7 S and 5 S preparations. The 3·5 S fragments differed from the 5 S fragments only by their content in cystine. 3.7 S , 5 S and 3·5 S preparations were effective as toxine neutralizing antibodies. The 3·5 S preparations, however, showed a lower specific activity. 4. The T -components and their fragments proved to be species specif1. They showed, however, quantitative differences. The homologous antigens provoked stronger anaphylactic reactions in guinea pigs. 5. In amino acid, fingerprints and carbohydrate analyses no differences have been found between diptheria and tetanus 7 S T -components and fragments. These findings, however, do not allow the conclusion, whether the antibody specificity is based on the primary structure or not. The amino acid analysis suggests that the T -component is more related to the γG-globulin than to the γA-globulin fraction of human serum.