Antibodies as immunological probes for studying the denaturation of HBsAg.

Radioimmunoassays were developed for antibodies to denaturated forms of HBsAg (reduced and alkylated in an isotonic buffer (RAHBs) or in 8 M urea-HBs) or reduced in 8M urea but not alkylated). These tests revealed that intact HBsAg and RA-HBs shared common antigenic determinants, termed Re[Imai et al, 1974]. Anti-Re is elicited in the course of immune response to intact HBsAg in humans and experimental animals. Denaturation in 8 M urea and alkylation causes the appearance of additional antigenic determinants, the specificity of which is affected by the reagent used for alkylation. Reduction in 8 M urea followed by treatment with iodoacetate reveals antigenic sites common for HBsAg and some human serum proteins. Antibodies specific for the Le Bouvier determinants of HBsAg are probably not the appropriate probe for detection of primary translational products of the hepatitis B virus genome.