Biochemical characterization and biologic activities of 82- and 86-kDa tumor antigens isolated from a methylcholanthrene-induced sarcoma, CII-7.

Two tumor-specific antigens, with molecular weights of approximately 82 and 86 kDa, have been isolated and purified to apparent homogeneity from the methylcholanthrene-induced sarcoma, CII-7. The method of purification used was essentially that previously employed for the isolation of the 82- and 86-kDa antigens from the Meth A sarcoma and the 86-kDa antigen from mKSA sarcoma. Cytosolic fractions were subjected to hexylamine agarose chromatography, Sepharose S-300 filtration and hydroxylapatite chromatography. A final step, HPLC-DEAE chromatography, was necessary for the purification of the 82-kDa protein. Both isolated antigens retained their specific immunogenicity for CII-7 as determined by in vivo tumor rejection assays, and failed to influence the growth of other syngeneic sarcomas, CI-4, CII-10 and mKSA, which have their own unique TATA. The 82- and 86-kDa antigens appear to be distinct proteins that are well conserved in nature and may represent members of distinct families of TATA.