STRUCTURE OF TYPE 5 ADENOVIRUS. II. FINE STRUCTURE OF VIRUS SUBUNITIS. MORPHOLOGIC RELATIONSHIP OF STRUCTURAL SUBUNITS TO VIRUS-SPECIFIC SOLUBLE ANTIGENS FROM INFECTED CELLS.

Purified type 5 adenovirus was disrupted at pH 10.5 and the capsid shown to be comprised of two characteristic morphological subunits: (a) Hollow, polygonal structures corresponding to the virus capsomeres seen in preparation of purified virus and (b) thread-like strands also identifiable in preparations of purified virus. These structures were compared morphologically with purified preparations of the group- and type-specific soluble antigens characteristically produced in mammalian cells infected with adenoviruses. The group-specific soluble antigen was a homogeneous preparation of hollow, polygonal rods identical with the virus capsomeres. The type-specific soluble antigen corresponded to the thread- or fiber-like components of the purified virus particle. Inspection of disrupted virus preparations confirmed earlier immunological data which indicated that the major virus antigen was the group-specific soluble antigen. These data provide convincing evidence for the hypothesis that the adenovirus-induced soluble antigens represent virus subunits produced in excess.