Isolation and comparative chemical study of structural proteins of the adenoviruses 2 and 5: hexon and fiber antigens.

Abstract

The hexon and fiber antigens of the adenoviruses types 2 and 5 have been extensively purified by a four step procedure comprising freon extraction, neutral salt precipitation, gel filtration chromatography and preparative liquid film electrophoresis. The physical and chemical properties of these two antigens isolated from two adenoviruses belonging to the same immunological subgoup were compared. The hexon antigen is constituted of at least four fractions. It was demonstrated that this apparent heterogeneity corresponds in fact to a series of polymers. The sedimentation coefficient of the monomer is about 11 S. The adenoviruses types 2 and 5 hexon and fiber antigens have similar chemical compositions. The similarity between the types 2 and 5 hexon antigens postulated from immunological studies and from the amino acid compositions was confirmed by peptide “finger-prints” of enzymic hydrolyzates. The results of the biochemical studies suggest that the hexon antigen is constituted of one single polypeptide chain, whereas the fiber antigen is constituted of several peptidic chains.