Proteins of vesicular stomatitis virus. II. Immunological comparisons of viral antigens.

The antigens of the nucleoprotein core and the coat of vesicular stomatitis virus (VSV) particles of the Indiana serotype were prepared and purified by sucrose gradient fractionation. Antibody was prepared separately to each of the two antigen fractions. By immunological procedures, it was shown that soluble antigens of VSV preparations sedimenting at 20S and in the leading edge of the 6S region are antigenically related to VP3, the protein of the virus core, whereas the 6S soluble antigen cross-reacts only with viral coat antibodies. These results confirm previous results obtained by polyacrylamide gel analysis of the antigens. It has further been demonstrated that the 6S antigen is a glycoprotein. Comparing antigens of the New Jersey and Indiana serotype showed that the coat antigens of virus particles and the 6S antigen are immunologically distinct in the two serotypes. In complement-fixation tests, the core antigens and the soluble 20S antigens from one serotype showed a cross-reaction with antiserum prepared against core proteins of the other serotype.