THE LS-ANTIGEN OF VACCINIA : II. ISOLATION OF A SINGLE SUBSTANCE CONTAINING BOTH L- AND S-ACTIVITY

Area of Science:

• Virology
• Immunology
• Biochemistry

Background:

• Vaccinia virus filtrates contain soluble substances with antigenic properties.
• Previous studies indicated complexity in vaccinia virus soluble antigens.

Purpose of the Study:

• To isolate and characterize the components responsible for L- and S-activity in vaccinia virus filtrates.
• To elucidate the antigenic structure of vaccinia virus soluble components.

Main Methods:

• Electrophoresis was used to separate components.
• Solubility changes with pH were exploited for purification.
• Serological tests (precipitation, inhibition) and ultracentrifugation were employed for characterization.

Main Results:

• Four distinct components were identified in vaccinia virus filtrate.
• A single component, LS-antigen, was found to possess both L- and S-activity.
• LS-antigen is a homogeneous protein molecule with two distinct antigenic sites (L and S).
• Differential heating and alkali treatment selectively modified the L or S portions of the LS-antigen, affecting precipitation but not necessarily binding.

Conclusions:

• Vaccinia virus LS-antigen is a single protein molecule with dual antigenic specificities (L and S).
• The L and S antigenic determinants are distinct yet associated within the same molecule.
• Understanding LS-antigen structure provides insights into vaccinia virus antigenicity and immune response.