Antibody formation for malignant tumor. Ⅲ. Antigenicity of peptide of ribosomal digest in Ehrlich ascites tumor

Antigenicity of the peptide of ribosomal digest in Ehrlich ascites tumor was studied. The peptide was purified by DEAE Sephadex A-50 column chromatography. The peptide was electrophoretically basic, single, and 1.32 S20w sedimentation coefficient with poor content of tyrosine and phenylalanine. The maximum absorbancy was at 267 mμ. Mice and rabbits were immunized with the mixture of the purified peptide with Freund's complete adjuvant. The inhibitory effect of immune γ-globulin on the tumor growth was demonstrated in vitro cultured JTC-11 cells. A single precipitin line was observed between rabbit antiserum and tumor cell extract of Ehrlich ascites cells in ouchterlony double diffusion chamber and immunoelectrophoresis. The sedimentation coefficient of the effective fraction in immune-serum was 17 S20w. The precipitin line was observed at β2-γ region in immunoelectrophoresis.