Complex formation of class I transplantation antigens and a viral glycoprotein.

Indirect immunoprecipitations of labeled glycoproteins from the adenovirus-transformed rat cell line A2T2C4 and from adenovirus-infected HeLa cells revealed that the class I major histocompatibility antigens co-precipitated with the viral E19 protein. The degree of co-precipitation was highly dependent on the antiserum used. The identity of the co-precipitated components was verified by peptide mapping and radiochemical amino acid sequencing. Cell-free translation of mRNA for the E19 protein and the class I antigen heavy chains demonstrated that the E19 protein-class I antigen interaction is an inherent property of the participating components. In intact cells the virus protein and the transplantation antigens form large complexes, held together by weak, noncovalent interactions.